Official business surveys form the basis for national and regional business statistics and are thus of great importance for analysing the state and performance of the economy. However, both the heterogeneity of business data and their high dynamics pose a particular challenge to the feasibility of sampling and the quality of the resulting estimates. A widely used sampling frame for creating the design of an official business survey is an extract from an official business register. However, if this frame does not accurately represent the target population, frame errors arise. Amplified by the heterogeneity and dynamics of business populations, these errors can significantly affect the estimation quality and lead to inefficiencies and biases. This dissertation therefore deals with design-based methods for optimising business surveys with respect to different types of frame errors. First, methods for adjusting the sampling design of business surveys are addressed. These approaches integrate auxiliary information about the expected structures of frame errors into the sampling design. The aim is to increase the number of sampled businesses that are subject to frame errors. The element-specific frame error probability is estimated based on auxiliary information about frame errors observed in previous samples. The approaches discussed consider different types of frame errors and can be incorporated into predefined designs with fixed strata. As the second main pillar of this work, methods for adjusting weights to correct for frame errors during estimation are developed and investigated. As a result of frame errors, the assumptions under which the original design weights were determined based on the sampling design no longer hold. The developed methods correct the design weights taking into account the errors identified for sampled elements. Case-number-based reweighting approaches, on the one hand, attempt to reconstruct the unknown size of the individual strata in the target population. In the context of weight smoothing methods, on the other hand, design weights are modelled and smoothed as a function of target or auxiliary variables. This serves to avoid inefficiencies in the estimation due to highly scattering weights or weak correlations between weights and target variables. In addition, possibilities of correcting frame errors by calibration weighting are elaborated. Especially when the sampling frame shows over- and/or undercoverage, the inclusion of external auxiliary information can provide a significant improvement of the estimation quality. For those methods whose quality cannot be measured using standard procedures, a procedure for estimating the variance based on a rescaling bootstrap is proposed. This enables an assessment of the estimation quality when using the methods in practice. In the context of two extensive simulation studies, the methods presented in this dissertation are evaluated and compared with each other. First, in the environment of an experimental simulation, it is assessed which approaches are particularly suitable with regard to different data situations. In a second simulation study, which is based on the structural survey in the services sector, the applicability of the methods in practice is evaluated under realistic conditions.

Behavioural traces from interactions with digital technologies are diverse and abundant. Yet, their capacity for theory-driven research is still to be constituted. In the present cumulative dissertation project, I deliberate the caveats and potentials of digital behavioural trace data in behavioural and social science research. One use case is online radicalisation research. The three studies included, set out to discern the state-of-the-art of methods and constructs employed in radicalization research, at the intersection of traditional methods and digital behavioural trace data. Firstly, I display, based on a systematic literature review of empirical work, the prevalence of digital behavioural trace data across different research strands and discern determinants and outcomes of radicalisation constructs. Secondly, I extract, based on this literature review, hypotheses and constructs and integrate them to a framework from network theory. This graph of hypotheses, in turn, makes the relative importance of theoretical considerations explicit. One implication of visualising the assumptions in the field is to systematise bottlenecks for the analysis of digital behavioural trace data and to provide the grounds for the genesis of new hypotheses. Thirdly, I provide a proof-of-concept for incorporating a theoretical framework from conspiracy theory research (as a specific form of radicalisation) and digital behavioural traces. I argue for marrying theoretical assumptions derived from temporal signals of posting behaviour and semantic meaning from textual content that rests on a framework from evolutionary psychology. In the light of these findings, I conclude by discussing important potential biases at different stages in the research cycle and practical implications.

Traditional workflow management systems support process participants in fulfilling business tasks through guidance along a predefined workflow model. Flexibility has gained a lot of attention in recent decades through a shift from mass production to customization. Various approaches to workflow flexibility exist that either require extensive knowledge acquisition and modelling effort or an active intervention during execution and re-modelling of deviating behaviour. The pursuit of flexibility by deviation is to compensate both of these disadvantages through allowing alternative unforeseen execution paths at run time without demanding the process participant to adapt the workflow model. However, the implementation of this approach has been little researched so far. This work proposes a novel approach to flexibility by deviation. The approach aims at supporting process participants during the execution of a workflow through suggesting work items based on predefined strategies or experiential knowledge even in case of deviations. The developed concepts combine two renowned methods from the field of artificial intelligence - constraint satisfaction problem solving with process-oriented case-based reasoning. This mainly consists of a constraint-based workflow engine in combination with a case-based deviation management. The declarative representation of workflows through constraints allows for implicit flexibility and a simple possibility to restore consistency in case of deviations. Furthermore, the combined model, integrating procedural with declarative structures through a transformation function, increases the capabilities for flexibility. For an adequate handling of deviations the methodology of case-based reasoning fits perfectly, through its approach that similar problems have similar solutions. Thus, previous made experiences are transferred to currently regarded problems, under the assumption that a similar deviation has been handled successfully in the past. Necessary foundations from the field of workflow management with a focus on flexibility are presented first. As formal foundation, a constraint-based workflow model was developed that allows for a declarative specification of foremost sequential dependencies of tasks. Procedural and declarative models can be combined in the approach, as a transformation function was specified that converts procedural workflow models to declarative constraints. One main component of the approach is the constraint-based workflow engine that utilizes this declarative model as input for a constraint solving algorithm. This algorithm computes the worklist, which is proposed to the process participant during workflow execution. With predefined deviation handling strategies that determine how the constraint model is modified in order to restore consistency, the support is continuous even in case of deviations. The second major component of the proposed approach constitutes the case-based deviation management, which aims at improving the support of process participants on the basis of experiential knowledge. For the retrieve phase, a sophisticated similarity measure was developed that integrates specific characteristics of deviating workflows and combines several sequence similarity measures. Two alternative methods for the reuse phase were developed, a null adaptation and a generative adaptation. The null adaptation simply proposes tasks from the most similar workflow as work items, whereas the generative adaptation modifies the constraint-based workflow model based on the most similar workflow in order to re-enable the constraint-based workflow engine to suggest work items. The experimental evaluation of the approach consisted of a simulation of several types of process participants in the exemplary domain of deficiency management in construction. The results showed high utility values and a promising potential for an investigation of the transfer on other domains and the applicability in practice, which is part of future work. Concluding, the contributions are summarized and research perspectives are pointed out.

Instead of presuming only local interaction, we assume nonlocal interactions. By doing so, mass at a point in space does not only interact with an arbitrarily small neighborhood surrounding it, but it can also interact with mass somewhere far, far away. Thus, mass jumping from one point to another is also a possibility we can consider in our models. So, if we consider a region in space, this region interacts in a local model at most with its closure. While in a nonlocal model this region may interact with the whole space. Therefore, in the formulation of nonlocal boundary value problems the enforcement of boundary conditions on the topological boundary may not suffice. Furthermore, choosing the complement as nonlocal boundary may work for Dirichlet boundary conditions, but in the case of Neumann boundary conditions this may lead to an overfitted model. In this thesis, we introduce a nonlocal boundary and study the well-posedness of a nonlocal Neu- mann problem. We present sufficient assumptions which guarantee the existence of a weak solution. As in a local model our weak formulation is derived from an integration by parts formula. However, we also study a different weak formulation where the nonlocal boundary conditions are incorporated into the nonlocal diffusion-convection operator. After studying the well-posedness of our nonlocal Neumann problem, we consider some applications of this problem. For example, we take a look at a system of coupled Neumann problems and analyze the difference between a local coupled Neumann problems and a nonlocal one. Furthermore, we let our Neumann problem be the state equation of an optimal control problem which we then study. We also add a time component to our Neumann problem and analyze this nonlocal parabolic evolution equation. As mentioned before, in a local model mass at a point in space only interacts with an arbitrarily small neighborhood surrounding it. We analyze what happens if we consider a family of nonlocal models where the interaction shrinks so that, in limit, mass at a point in space only interacts with an arbitrarily small neighborhood surrounding it.

Intensiv diskutierte Aspekte der Politikwissenschaft heben zunehmend die Bedeutung von Strategiefähigkeit zur erfolgreichen Durchführung von Wahlkämpfen für Parteien hervor. Der Widerspruch der mit den Implikationen der modernen Mediengesellschaft eingehergehenden unterstellten Akteursfähigkeit der Parteien und ihrer kollektiven heterogenen Interessens- und Organisationsvielfalt bleibt dabei bestehen. Die Fokussierung der Parteien auf das Ziel der Stimmenmaximierung bringt unter den sich wandelnden Rahmenbedingungen Veränderungen der Binnenstrukturen mit sich. So diskutieren Parteienforscher seit Längerem die Notwendigkeit eines vierten Parteitypus als Nachfolger von Kirchheimers Volkspartei (1965). Verschiedene dieser Ansätze berücksichtigen primär die Wahlkampffokussierung der Parteien, während andere vor allem auf den gesteigerten Strategiebedarf abzielen. Auch die Wechselwirkungen mit den Erfordernissen der Mediengesellschaft sowie Auswirkungen des gesellschaftlichen Wandels stehen im Vordergrund zahlreicher Untersuchungen. Die Arbeit von Uwe Jun (2004), der mit dem Modell der professionalisierten Medienkommunikationspartei auch die organisatorischen und programmatischen Transformationsaspekte des Parteiwandels beleuchtet, liefert einen bemerkenswerten Beitrag zur Party-Change-Debatte und bietet durch die angeschlossene vergleichende exemplarische Fallstudie eine praxisnahe Einordnung. Die geringe empirische Relevanz, die Jun seinem Parteityp anhand der Untersuchung von SPD und New Labor zwischen 1995 und 2005 bestätigt, soll in dieser Arbeit versucht werden zu relativieren, in dem der Parteiwandel der deutschen Großparteien seit der Wiedervereinigung durch die Untersuchung ihrer Wahlkampffähigkeit aufgezeigt wird. Anhand eines längsschnittlichen Vergleiches der Bundestagswahlkämpfe von SPD und CDU zwischen 1990 und 2013 soll die Plausibilität dieses vierten Parteitypus überprüft werden. Hierdurch soll die Entwicklung der Strategie- und Wahlkampffähigkeit beider Großparteien in den Bundestagswahlkämpfen seit 1990 untersucht und die Ergebnisse miteinander verglichen und in Bezug auf den Parteiwandel eingeordnet werden. Dass sich Parteien genau wie ihre gesellschaftliche und politische Umwelt im Wandel befinden, ist nicht zu bestreiten und seit Langem viel diskutierter Gegenstand der Parteienforschung. „Niedergangsdiskussion“, Mitgliederschwund, Nicht- und Wechselwähler, Politik- und Parteienverdrossenheit, Kartellisierung und Institutionalisierung von Parteien sind nur einige der in diesem Kontext geläufigen Schlagwörter. Prozesse der Individualisierung, Globalisierung und Mediatisierung führen zu veränderten Rahmenbedingungen, unter denen Parteien sich behaupten müssen. Diese Veränderungen in der äußeren Umwelt wirken sich nachhaltig auf das parteipolitische Binnenleben, auf Organisationsstrukturen und Programmatik aus. Die Parteienforschung hat daher schon vor zwanzig Jahren begonnen, ein typologisches Nachfolgemodell der Volkspartei zu diskutieren, das diesen Wandel berücksichtigt. Verschiedene typologische Konstruktionen von z. B. Panebianco (1988), Katz und Mair (1995) oder von Beyme erfassen (2000) wichtige Facetten des Strukturwandels politischer Parteien und stellen mehrheitlich plausible typologische Konzepte vor, die die Parteien in ihrem Streben nach Wählerstimmen und Regierungsmacht zutreffend charakterisieren. Die Parteienforschung stimmt bezüglich des Endes der Volksparteiära mehrheitlich überein. Bezüglich der Nachfolge konnte sich unter den neueren vorgeschlagenen Typen jedoch kein vierter Typ als verbindliches Leitmodell etablieren. Bei genauerer Betrachtung weichen die in den verschiedenen Ansätzen für einen vierten Parteitypen hervorgehobenen Merkmale (namentlich Professionalisierung des Parteiapparates, die Berufspolitikerdominanz, Verstaatlichung und Kartellbildung sowie die Fixierung auf die Medien) wenig von jüngeren Modellvorschlägen ab und bedürfen daher mehr einer Ergänzung. Die in der Regel mehrdimensionalen entwicklungstypologischen Verlaufstypen setzten seit den 1980er Jahren unterschiedliche Schwerpunkte und warten mit vielen Vorschlägen der Einordnung auf. Einer der jüngsten Ansätze von Uwe Jun aus dem Jahr 2004, der das typologische Konzept der professionalisierten Medienkommunikationspartei einführt, macht deutlich, dass die Diskussion um Gestalt und Ausprägungen des vierten Parteityps noch in vollem Gang und für weitere Vorschläge offen ist – der „richtige“ Typ also noch nicht gefunden wurde. Jun bleibt in seiner Untersuchung den zentralen Transformationsleitfragen nach der Ausgestaltung der Parteiorganisation, der ideologisch-programmatischen Orientierung und der strategisch-elektoralen Wählerorientierung verhaftet und setzt diese Elemente in den Fokus sich wandelnder Kommunikationsstrategien. Die bisher in parteitypologischen Arbeiten mitunter vernachlässigte Komponente der strukturellen Strategiefähigkeit als Grundlage zur Entwicklung ebensolcher Reaktionsstrategien wird bei Jun angestoßen und soll in dieser Arbeit aufgegriffen und vertieft werden. Der aktuellen Partychange-Diskussion zum Trotz scheint die Annahme, dass Parteien, die sich verstärkt der Handlungslogik der Massenmedien unterwerfen, deren strategischen Anforderungen durch interne Adaptionsverfahren auch dauerhaft gerecht zu werden vermögen, nicht immer zutreffend. Die Veränderungen der Kommunikationsstrategien als Reaktion auf gesamtgesellschaftliche Wandlungsprozesse stehen zwar im Zentrum der Professionalisierungsbemühungen der politischen Akteure, bleiben aber in ihrer Wirkung eingeschränkt. Wenngleich das Wissen in den Parteien um die Notwendigkeiten (medialer) Strategiefähigkeit besteht und die Parteien hierauf mit Professionalisierung, organisatorischen und programmatischen Anpassungsleistungen und der Herausbildung strategischer Zentren reagieren, so ist mediengerechtes strategisches Agieren noch lange keine natürliche Kernkompetenz der Parteien. Vor allem in Wahlkampfzeiten, die aufgrund abnehmender Parteibindungen und zunehmender Wählervolatilität für die Parteien zum eigentlich zentralen Moment der Parteiendemokratie werden, wird mediengerechtes Handeln zum wesentlichen Erfolgsfaktor. Strategiefähigkeit wird hierbei zur entscheidenden Voraussetzung und scheint zudem in diesen Phasen von den Parteien erfolgreicher umgesetzt zu werden als im normalen politischen Alltag. Die wahlstrategische Komponente findet in Juns typologischer Konstruktion wenig Beachtung und soll in dieser Arbeit daher als ergänzendes Element hinzugefügt werden. Arbeitshypothese Die beiden deutschen Großparteien berufen sich auf unterschiedliche Entstehungsgeschichten, die sich bis in die Gegenwart auf die Mitglieder-, Issue- und Organisationsstrukturen von SPD und CDU auswirken und die Parteien in ihren Anpassungsleistungen an die sich wandelnde Gesellschaft beeinflussen. Beide Parteien versuchen, auf die veränderten sozialen und politischen Rahmenbedingungen und den daraus resultierenden Bedeutungszuwachs von politischer Kommunikationsplanung mit einem erhöhten Maß an Strategiefähigkeit und kommunikativer Kompetenz zu reagieren. Diese Entwicklung tritt seit der deutschen Wiedervereinigung umso stärker in Augenschein, als dass nach 1990 die Bindekraft der Volksparteien nochmals nachließ, sodass die Parteien sich zunehmend gezwungen sehen, die „lose verkoppelten Anarchien“ in wahlstrategische Medienkommunikationsparteien zu transformieren. Diesen vierten Parteityp kennzeichnet vor allem die zunehmende Bemühung um Strategiefähigkeit, die mittels Organisationsstrukturen und programmatischer Anpassungsleistungen die Effizienz der elektoralen Ausrichtung verbessern soll. Insgesamt geht die Party-Change-Forschung davon aus, dass die Parteien sich zunehmend angleichen. Dies gilt es in dieser Studie zu überprüfen. Unter Berücksichtigung unterschiedlicher Entwicklungspfade kann vermutet werden, dass auch die Transformationsprozesse bei SPD und CDU in unterschiedlicher Weise verlaufen. Wenngleich die SPD über einen höheren Strategiebedarf und die größere Innovationsbereitschaft zu verfügen scheint, werden auf Seiten der Union potentiell strategiefähigere Strukturen vermutet, die die erfolgreiche Umsetzung von Wahlkampfstrategien erleichtern. Die historische Entwicklung und der Aspekt der Historizität spielen in diesem Kontext eine Rolle. Zusätzlich spielen individuelle Führungspersönlichkeiten eine zentrale Rolle in innerparteilichen Transformationsprozessen, welche für die Ausprägung strategiefähiger Strukturen oftmals von größerer Bedeutung sind als institutionalisierte Strukturen. Im Vordergrund steht die Untersuchung des Parteiwandels anhand der Veränderung der Kommunikationsstrategien der Parteien im Allgemeinen sowie der Strategiefähigkeit in Wahlkämpfen im Besonderen, da diese als zentrale Merkmale für den vierten Parteityp in Anlehnung an die Professionelle Medienkommunikationspartei (Jun 2004) gewertet werden sollen. Strategiefähigkeit soll dabei anhand der Kriterien des Umgangs der Parteien mit Programmatik, Organisation und externen Einflussfaktoren in Wahlkämpfen operationalisiert werden. Die Analyse untersucht sowohl das Handeln einzelner Personen wie auch die Rolle der Partei als Gesamtorganisation. Die Arbeit besteht aus zehn Kapiteln und gliedert sich in zwei Blöcke: einen theoretisch konzeptionellen Teil, der die in der Perspektive dieser Arbeit zentralen Grundlagen und Rahmenbedingungen zusammenführt sowie die sich daran anschließende Untersuchung der Konzeption und Implementation von Kommunikationskampagnen im Wahlkampf seit 1990. Das aktuell in die politikwissenschaftliche Diskussion eingebrachte Feld der politischen Strategiefähigkeit (Raschke/Tils 2007) wird in ausführlicher theoretischer Grundlegung bisher zwar mit den Implikationen der Medienkommunikation und damit einhergehend auch den organisatorischen und programmatischen Strukturmerkmalen der Parteien verknüpft, diese erfolgte allerdings oft ohne vertiefte Berücksichtigung des Parteiwandels. Dies soll in diesem Beitrag daher versucht werden. Der Diskursanalyse des Strategiebegriffes in Wahlkampfsituationen folgt die detaillierte Darstellung der drei Operationalisierungsparameter, die in die Festlegung des Parteityps münden. Die Diskussion idealtypischer Wahlkampfmodelle als theoretischer Bezugsrahmen für die Bewertung der Wahlkampagnen ergänzt den theoretisch-konzeptionellen Bezugsrahmen. Die insgesamt in der Literatur in ihren Ausführungen oftmals normativ gestalteten Darstellungen idealtypischer politischer Strategie sollen im letzten Teil der Arbeit auf ihre Umsetzbarkeit im parteipolitischen Alltag überprüft werden und dies nicht nur anhand einzelner, mit einander nicht in Zusammenhang stehender Ereignisse, sondern anhand der sich periodisch unter vergleichbaren Bedingungen wiederholenden Wahlkämpfe. Dafür werden die jeweiligen Ausgangs- und Rahmenbedingungen der einzelnen Wahlkämpfe sowie die zuvor dargelegten Elemente professionalisierter Wahlkampagnen für die Wahlkampagnen von SPD und CDU seit 1990 dargestellt. Aus diesen Gegenüberstellungen soll im Anschluss der längsschnittliche Vergleich der Strategiefähigkeit und Kommunikationskompetenz von SPD und CDU abgeleitet werden

Die Dissertation beschäftigt sich mit einer neuartigen Art von Branch-and-Bound Algorithmen, deren Unterschied zu klassischen Branch-and-Bound Algorithmen darin besteht, dass das Branching durch die Addition von nicht-negativen Straftermen zur Zielfunktion erfolgt anstatt durch das Hinzufügen weiterer Nebenbedingungen. Die Arbeit zeigt die theoretische Korrektheit des Algorithmusprinzips für verschiedene allgemeine Klassen von Problemen und evaluiert die Methode für verschiedene konkrete Problemklassen. Für diese Problemklassen, genauer Monotone und Nicht-Monotone Gemischtganzzahlige Lineare Komplementaritätsprobleme und Gemischtganzzahlige Lineare Probleme, präsentiert die Arbeit verschiedene problemspezifische Verbesserungsmöglichkeiten und evaluiert diese numerisch. Weiterhin vergleicht die Arbeit die neue Methode mit verschiedenen Benchmark-Methoden mit größtenteils guten Ergebnissen und gibt einen Ausblick auf weitere Anwendungsgebiete und zu beantwortende Forschungsfragen.

Diese Dissertation beschäftigt sich mit der Fragestellung, ob und wie Intersektionalität als analytische Perspektive für literarische Texte eine nützliche Ergänzung für ethnisch geordnete Literaturfelder darstellt. Diese Fragestellung wird anhand der Analyse dreier zeitgenössischer chinesisch-kanadischer Romane untersucht. In der Einleitung wird die Relevanz der Themenbereiche Intersektionalität und asiatisch-kanadische Literatur erörtert. Das darauffolgende Kapitel bietet einen historischen Überblick über die chinesisch-kanadische Einwanderung und geht detailliert auf die literarischen Produktionen ein. Es wird aufgezeigt, dass, obwohl kulturelle Güter auch zur Artikulation von Ungleichheitsverhältnissen aufgrund von zugeschriebener ethnischer Zugehörigkeit entstehen, ein Diversifizierungsbestreben innerhalb der literarischen Gemeinschaft von chinesisch-kanadischen Autor:innen identifiziert werden kann. Das dritte Kapitel widmet sich dem Begriff „Intersektionalität“ und stellt, nach einer historischen Einordnung des Konzeptes mit seinen Ursprüngen im Black Feminism, Intersektionalität als bindendes Element zwischen Postkolonialismus, Diversität und Empowerment dar – Konzepte, die für die Analyse (kanadischer) Literatur in dieser Dissertation von besonderer Relevanz sind. Anschließend wird die Rolle von Intersektionalität in der Literaturwissenschaft aufgegriffen. Die darauffolgenden exemplarischen Analysen von Kim Fus For Today I Am a Boy, Wayson Choys The Jade Peony und Yan Lis Lily in the Snow veranschaulichen die vorangegangen methodischen Überlegungen. Allen drei Romanen vorangestellt ist die Kontextualisierung des jeweiligen Werkes als chinesisch-kanadisch, aber auch bisher vorgenommene Überlegungen, die diese Einordnung infrage stellen. Nach einer Zusammenfassung des Inhalts folgt eine intersektionale Analyse auf der inhaltlichen Ebene, die in den familiären und weiteren sozialen Bereich unterteilt ist, da sich die Hierarchiemechanismen innerhalb dieser Bereiche unterscheiden oder gegenseitig verstärken, wie aus den Analysen hervorgeht. Anschließend wird die formale Analyse mit einem intersektionalen Schwerpunkt in einem separaten Unterkapitel näher beleuchtet. Ein drittes Unterkapitel widmet sich einem dem jeweiligen Roman spezifischen Aspekt, der im Zusammenhang mit einer intersektionalen Analyse von besonderer Relevanz ist. Die Arbeit schließt mit einem übergreifenden Fazit, welches die wichtigsten Ergebnisse aus der Analyse zusammenfasst und mit weiteren Überlegungen zu den Implikationen dieser Dissertation, vor allem im Hinblick auf sogenannte kanadische „master narratives“, die eine weitreichende, kontextuelle Relevanz für das Arbeiten mit literarischen Texten aufweisen und durch einen intersektionalen literarischen Ansatz in Zukunft gegebenenfalls gewinnbringend ergänzt werden können.

This thesis deals with REITs, their capital structure and the effects on leverage that regulatory requirements might have. The data used results from a combination of Thomson Reuters data with hand-collected data regarding the REIT status, regulatory information and law variables. Overall, leverage is analysed across 20 countries in the years 2007 to 2018. Country specific data, manually extracted from yearly EPRA reportings, is merged with company data in order to analyse the influence of different REIT restrictions on a firm's leverage. Observing statistically significant differences in means across NON-REITs and REITs, causes motivation for further investigations. My results show that variables beyond traditional capital structure determinants impact the leverage of REITs. I find that explicit restrictions on leverage and the distribution of profits have a significant effect on leverage decisions. This supports the notion that the restrictions from EPRA reportings are mandatory. I test for various combinations of regulatory variables that show both in isolation as well as in combination significant effects on leverage. My main result is the following: Firms that operate under regulation that specifies a maximum leverage ratio, in addition to mandatory high dividend distributions, have on average lower leverage ratios. Further the existence of sanctions has a negative effect on REITs' leverage ratios, indicating that regulation is binding. The analysis clearly shows that traditional capital structure determinants are of second order relevance. This relationship highlights the impact on leverage and financing decisions caused by regulation. These effects are supported by further analysis. Results based on an event study show that REITs have statistically lower leverage ratios compared to NON-REITs. Based on a structural break model, the following effect becomes apparent: REITs increase their leverage ratios in years prior REIT status. As a consequence, the ex ante time frame is characterised by a bunker and adaption process, followed by the transformation in the event. Using an event study and a structural break model, the analysis highlights the dominance of country-specific regulation.

The German Mittelstand is closely linked to the success of the German economy. Mittelstand firms, thereof numerous Hidden Champions, significantly contribute to Germany’s economic performance, innovation, and export strength. However, the advancing digitalization poses complex challenges for Mittelstand firms. To benefit from the manifold opportunities offered by digital technologies and to defend or even expand existing market positions, Mittelstand firms must transform themselves and their business models. This dissertation uses quantitative methods and contributes to a deeper understanding of the distinct needs and influencing factors of the digital transformation of Mittelstand firms. The results of the empirical analyses of a unique database of 525 mid-sized German manufacturing firms, comprising both firm-related information and survey data, show that organizational capabilities and characteristics significantly influence the digital transformation of Mittelstand firms. The results support the assumption that dynamic capabilities promote the digital transformation of such firms and underline the important role of ownership structure, especially regarding family influence, for the digital transformation of the business model and the pursuit of growth goals with digitalization. In addition to the digital transformation of German Mittelstand firms, this dissertation examines the economic success and regional impact of Hidden Champions and hence, contributes to a better understanding of the Hidden Champion phenomenon. Using quantitative methods, it can be empirically proven that Hidden Champions outperform other mid-sized firms in financial terms and promote regional development. Consequently, the results of this dissertation provide valuable research contributions and offer various practical implications for firm managers and owners as well as policy makers.

While humans find it easy to process visual information from the real world, machines struggle with this task due to the unstructured and complex nature of the information. Computer vision (CV) is the approach of artificial intelligence that attempts to automatically analyze, interpret, and extract such information. Recent CV approaches mainly use deep learning (DL) due to its very high accuracy. DL extracts useful features from unstructured images in a training dataset to use them for specific real-world tasks. However, DL requires a large number of parameters, computational power, and meaningful training data, which can be noisy, sparse, and incomplete for specific domains. Furthermore, DL tends to learn correlations from the training data that do not occur in reality, making DNNs poorly generalizable and error-prone. Therefore, the field of visual transfer learning is seeking methods that are less dependent on training data and are thus more applicable in the constantly changing world. One idea is to enrich DL with prior knowledge. Knowledge graphs (KG) serve as a powerful tool for this purpose because they can formalize and organize prior knowledge based on an underlying ontological schema. They contain symbolic operations such as logic, rules, and reasoning, and can be created, adapted, and interpreted by domain experts. Due to the abstraction potential of symbols, KGs provide good prerequisites for generalizing their knowledge. To take advantage of the generalization properties of KG and the ability of DL to learn from large-scale unstructured data, attempts have long been made to combine explicit graph and implicit vector representations. However, with the recent development of knowledge graph embedding methods, where a graph is transferred into a vector space, new perspectives for a combination in vector space are opening up. In this work, we attempt to combine prior knowledge from a KG with DL to improve visual transfer learning using the following steps: First, we explore the potential benefits of using prior knowledge encoded in a KG for DL-based visual transfer learning. Second, we investigate approaches that already combine KG and DL and create a categorization based on their general idea of knowledge integration. Third, we propose a novel method for the specific category of using the knowledge graph as a trainer, where a DNN is trained to adapt to a representation given by prior knowledge of a KG. Fourth, we extend the proposed method by extracting relevant context in the form of a subgraph of the KG to investigate the relationship between prior knowledge and performance on a specific CV task. In summary, this work provides deep insights into the combination of KG and DL, with the goal of making DL approaches more generalizable, more efficient, and more interpretable through prior knowledge.

Some of the largest firms in the DACH region (Germany, Austria, Switzerland) are (partially) owned by a foundation and/or a family office, such as Aldi, Bosch, or Rolex. Despite their growing importance, prior research neglected to analyze the impact of these intermediaries on the firms they own. This dissertation closes this research gap by contributing to a deeper understanding of two increasingly used family firm succession vehicles, through four empirical quantitative studies. The first study focuses on the heterogeneity in foundation-owned firms (FOFs) by applying a descriptive analysis to a sample of 169 German FOFs. The results indicate that the family as a central stakeholder in a family foundation fosters governance that promotes performance and growth. The second study examines the firm growth of 204 FOFs compared to matched non-FOFs from the DACH region. The findings suggest that FOFs grow significantly less in terms of sales but not with regard to employees. In addition, it seems that this negative effect is stronger for the upper than for the middle or lower quantiles of the growth distribution. Study three adopts an agency perspective and investigates the acquisition behavior within the group of 164 FOFs. The results reveal that firms with charitable foundations as owners are more likely to undertake acquisitions and acquire targets that are geographically and culturally more distant than firms with a family foundation as owner. At the same time, they favor target companies from the same or related industries. Finally, the fourth study scrutinizes the capital structure of firms owned by single family-offices (SFOs). Drawing on a hand-collected sample of 173 SFO-owned firms in the DACH region, the results show that SFO-owned firms display a higher long-term debt ratio than family-owned firms, indicating that SFO-owned firms follow trade-off theory, similar to private equity-owned firms. Additional analyses show that this effect is stronger for SFOs that sold their original family firm. In conclusion, the outcomes of this dissertation furnish valuable research contributions and offer practical insights for families navigating such intermediaries or succession vehicles in the long term.

The publication of statistical databases is subject to legal regulations, e.g. national statistical offices are only allowed to publish data if the data cannot be attributed to individuals. Achieving this privacy standard requires anonymizing the data prior to publication. However, data anonymization inevitably leads to a loss of information, which should be kept minimal. In this thesis, we analyze the anonymization method SAFE used in the German census in 2011 and we propose a novel integer programming-based anonymization method for nominal data. In the first part of this thesis, we prove that a fundamental variant of the underlying SAFE optimization problem is NP-hard. This justifies the use of heuristic approaches for large data sets. In the second part, we propose a new anonymization method belonging to microaggregation methods, specifically designed for nominal data. This microaggregation method replaces rows in a microdata set with representative values to achieve k-anonymity, ensuring each data row is identical to at least k − 1 other rows. In addition to the overall dissimilarities of the data rows, the method accounts for errors in resulting frequency tables, which are of high interest for nominal data in practice. The method employs a typical two-step structure: initially partitioning the data set into clusters and subsequently replacing all cluster elements with representative values to achieve k-anonymity. For the partitioning step, we propose a column generation scheme followed by a heuristic to obtain an integer solution, which is based on the dual information. For the aggregation step, we present a mixed-integer problem formulation to find cluster representatives. To this end, we take errors in a subset of frequency tables into account. Furthermore, we show a reformulation of the problem to a minimum edge-weighted maximal clique problem in a multipartite graph, which allows for a different perspective on the problem. Moreover, we formulate a mixed-integer program, which combines the partitioning and the aggregation step and aims to minimize the sum of chi-squared errors in frequency tables. Finally, an experimental study comparing the methods covered or developed in this work shows particularly strong results for the proposed method with respect to relative criteria, while SAFE shows its strength with respect to the maximum absolute error in frequency tables. We conclude that the inclusion of integer programming in the context of data anonymization is a promising direction to reduce the inevitable information loss inherent in anonymization, particularly for nominal data.

This thesis deals with the construction of investment screening mechanisms across the major economic powers in Europe and at the supranational level during the post-2015 period. The core puzzle at the heart of this research is how, in a traditional bastion of economic liberalism such as Europe, could a protectionist tool such as investment screening be erected in such a rapid manner. Within a few years, Europe went from a position of being highly welcoming towards foreign investment to increasingly implementing controls on it, with the focus on China. How are we to understand this shift in Europe? I posit that Europe’s increasingly protectionist shift on inward investment can be fruitfully understood using an economic realist approach, where the introduction of investment screening can be seen as part of a process of ‘balancing’ China’s economic rise and reasserting European competitiveness. China has moved from being the ‘workshop of the world’ to becoming an innovation-driven economy at the global technological frontier. As China has become more competitive, Europe, still a global economic leader, broadly situated at the technological frontier, has begun to sense a threat to its position, especially in the context of the fourth industrial revolution. A ‘balancing’ process has been set in motion, in which Europe seeks to halt and even reverse the narrowing competitiveness gap between it and China. The introduction of investment screening measures is part of this process.

This thesis contains three parts that are all connected by their contribution to research about the effects of trading apps on investment behavior. The primary motivation for this study is to investigate the previously undetermined consequences and effects of trading apps, which are a new phenomenon in the broker market, on the investment and risk behavior of Neobroker users. Chapter 2 addresses the characteristics of a typical Neobroker user and a former Neobroker user and the impact of trading apps on the investment and risk behavior of their users. The results show that Neobroker users are significantly more risk tolerant than the general German population and are influenced by trading apps regarding their investment and risk behavior. Low trading fees and the low minimum investment amount are the main reasons for the use of trading apps. Investors who stop using trading apps mostly stop investing altogether. Another worrying result is that financial literacy among all groups is low and most Neobroker users have wrong conceptions about how trading apps earn money. In general, the financial literacy of all groups considered in this chapter is surprisingly low. The third chapter investigates the effects of trading apps on investment behavior over time and compares the investment and risk behavior of Neobroker users and general investors. By using representative data of German Neobroker users, who were surveyed repeatedly over a 8-month time interval, it becomes possible to determine causal effects of the use of trading apps over time. In total, the financial literacy of Neobroker users increases with the longer use of a trading app. A worrying result is that the risk tolerance of Neobroker users rises significantly over time. Male Neobroker users gain a higher annual return (non-risk-adjusted) than female Neobroker users. In comparison to general investors, Neobroker users are significantly younger, more risk tolerant, more likely to buy derivatives and gain a higher annual return (non-risk-adjusted). The fourth chapter analyses the impact of personality traits on the investment and risk behavior of Neobroker users. The results show that the BIG-5 personality traits have an impact on the investment behavior of Neobroker users. Two personality traits, openness and conscientiousness, stand out the most, as these two have explanatory power over various aspects of the behavior of Neobroker users. In particular, whether they buy different financial products than planned, the time they inform themselves about financial markets, the variety of financial products owned, and the reasons to use a Neobroker. Surprisingly, the risk tolerance of Neobroker users and the reasons to invest are not connected to any personal dimension. Whether a participant uses a trading app or a traditional broker to invest is respectively influenced by different personality traits.

The positive consequences of performance pay on the wages and productivity have been well documented in the last decades. Yet, the increased pressure and work commitment associated with performance pay suggest that performance pay may have unintended negative consequences on worker’s health and well-being. As firms increasingly use performance pay worldwide, it becomes crucial to evaluate positive and negative consequences of performance pay. Thus, Chapters 2 – 4 of this doctoral thesis investigate the unintended adverse consequences of performance pay on stress, alcohol consumption, and loneliness, respectively. Chapter 5 investigates the positive role of performance pay on mitigating the overeducation wage penalty and enhancing labor market position of overeducated workers. In Chapter 2, together with John S. Heywood and Uwe Jirjahn, I examine the hypothesis that performance pay is positively associated with employee stress. Using unique survey data from the German Socio-Economic Panel, I find performance pay consistently and importantly associates with greater stress even controlling for a long list of economic, social, and personality characteristics. The finding also holds in instrumental variable estimations accounting for the potential endogeneity of performance pay. Moreover, I show that risk tolerance and locus of control moderate the relationship between performance pay and stress. Among workers receiving performance pay, the risk tolerant and those believing they can control their environment suffer to a lesser degree from stress. Chapter 3 examines the relationship between performance pay and alcohol use. Together with John S. Heywood and Uwe Jirjahn, I examine the hypothesis that alcohol use as “self-medication” is a natural response to the stress and uncertainty associated with performance pay. Using data from the German Socio-Economic Panel, I find that the likelihood of consuming each of four types of alcohol (beer, wine, spirits, and mixed drinks) is higher for those receiving performance pay even controlling for a long list of economic, social, and personality characteristics and in sensible instrumental variable estimates. I also show that the number of types of alcohol consumed is larger for those receiving performance pay and that the intensity of consumption increases. Moreover, I find that risk tolerance and gender moderate the relationship between performance pay and alcohol use. In Chapter 4, I examine the hypothesis that performance pay increases the risk of employee loneliness due to increased stress, job commitment, and uncooperativeness associated with performance pay. Using the German Socio-Economic Panel, I find that performance pay is positively associated with both the incidence and intensity of loneliness. Correspondingly, performance pay decreases the social life satisfaction of workers. The findings also hold in instrumental variable estimations addressing the potential endogeneity of performance pay and in various robustness checks. Interestingly, investigating the potential role of moderating factors reveals that the association between performance pay and loneliness is particularly large for private sector employees. Finally, in Chapter 5, I study the association between overeducation, performance pay, and wages. Overeducated workers are more productive and have higher wages in comparison to their adequately educated coworkers in the same jobs. However, they face a series of challenges in the labor market, including lower wages in comparison to their similarly educated peers who are in correctly matched jobs. Yet, less consensus exists over the adjustment mechanisms to overcome the negative consequences of overeducation. In this study, I examine the hypotheses that overeducated workers sort into performance pay jobs as an adjustment mechanism and that performance pay enhances their wages. Using the German Socio-Economic Panel, I show that overeducation associates with a higher likelihood of sorting into performance pay jobs and that performance pay moderates the wages of overeducated workers positively. It also holds in endogenous switching regressions accounting for the potential endogeneity of performance pay. Importantly, I show that the positive role of performance pay is particularly larger for the wages of overeducated women.

Information in der vorvertraglichen Phase – das heißt, Informationspflichten sowie Rechtsfolgen von Informationserteilung und -nichterteilung – in Bezug auf Kaufvertrag und Wahl des optionalen Instruments hat im Vorschlag der Europäischen Kommission für ein Gemeinsames Europäisches Kaufrecht (GEK; KOM(2011) 635) vielfältige Regelungen erfahren. Die vorliegende Arbeit betrachtet diese Regelungen auch in ihrem Verhältnis zu den Textstufen des Europäischen Privatrechts – Modellregeln und verbraucherschützende EU-Richtlinien – und misst sie an ökonomischen Rahmenbedingungen, die die Effizienz von Transaktionen gebieten und Grenzen des Nutzens von (Pflicht-)Informationen aufzeigen. Vom Grundsatz der Vertragsfreiheit ausgehend ist jeder Partei das Risiko zugewiesen, unzureichend informiert zu sein, während die Gegenseite nur punktuell zur Information verpflichtet ist. Zwischen Unternehmern bleibt es auch nach dem GEK hierbei, doch zwischen Unternehmer und Verbraucher wird dieses Verhältnis umgekehrt. Dort gelten, mit Differenzierung nach Vertragsschlusssituationen, umfassende Kataloge von Informationspflichten hinsichtlich des Kaufvertrags. Als Konzept ist dies grundsätzlich sinnvoll; die Pflichten dienen dem Verbraucherschutz, insbesondere der Informiertheit und Transparenz vor der Entscheidung über den Vertragsschluss. Teilweise gehen die Pflichten aber zu weit. Die Beeinträchtigung der Vertragsfreiheit des Unternehmers durch die Pflichten und die Folgen ihrer Verletzung lässt sich nicht vollständig mit dem Ziel des Verbraucherschutzes rechtfertigen. Durch das Übermaß an Information fördern die angeordneten Pflichten den Verbraucherschutz nur eingeschränkt; sie genügen nicht verhaltensökonomischen Maßstäben. Es empfiehlt sich daher, zwischen Unternehmern und Verbrauchern bestimmte verpflichtende Informationsinhalte ganz zu streichen, auf im konkreten Fall nicht erforderliche Information zu verzichten, erst nach Vertragsschluss relevante Informationen auf diese Zeit zu verschieben und die verbleibenden vorvertraglichen Pflichtinformationen in einer für den Verbraucher besser zu verarbeitenden Weise zu präsentieren. Von den einem Verbraucher zu erteilenden Informationen sollte stets verlangt werden, dass sie klar und verständlich sind; die Beweislast für ihre ordnungsgemäße Erteilung sollte generell dem Unternehmer obliegen. Neben die ausdrücklich angeordneten Informationspflichten treten ungeachtet der Verbraucher- oder Unternehmereigenschaft sowie der Käufer- oder Verkäuferrolle stark einzelfallabhängige Informationspflichten nach Treu und Glauben, die im Recht der Willensmängel niedergelegt sind. Hier ist der Grundsatz verwirklicht, dass mangelnde Information zunächst das eigene Risiko jeder Partei ist; berechtigtes Vertrauen und freie Willensbildung werden geschützt. Diese Pflichten berücksichtigen auch das Ziel der Effizienz und achten die Vertragsfreiheit. Das Vertrauen auf jegliche erteilten Informationen wird zudem dadurch geschützt, dass sie den Vertragsinhalt – allerdings in Verbraucherverträgen nicht umfassend genug – mitbestimmen können und dass ihre Unrichtigkeit sanktioniert wird. Die Verletzung jeglicher Arten von Informationspflichten kann insbesondere einen Schadensersatzanspruch sowie – über das Recht der Willensmängel – die Möglichkeit zur Lösung vom Vertrag nach sich ziehen. Das Zusammenspiel der unterschiedlichen Mechanismen führt allerdings zu Friktionen sowie zu Lücken in den Rechtsfolgen von Informationspflichtverletzungen. Daher empfiehlt sich die Schaffung eines Schadensersatzanspruchs für jede treuwidrig unterlassene Informationserteilung; hierdurch wird das Gebot von Treu und Glauben auch außerhalb des Rechts der Willensmängel zu einer eigentlichen einzelfallabhängigen Informationspflicht aufgewertet.

Income is one of the key indicators to measure regional differences, individual opportunities, and inequalities in society. In Germany, the regional distribution of income is a central concern, especially regarding persistent East-West, North-South, or urban-rural inequalities. Effective local policies and institutions require reliable data and indicators on regional inequality. However, its measurement faces severe data limitations: Inconsistencies in the existing microdata sources yield an inconclusive picture of regional inequality. While survey data provide a wide range of individual and household information but lack top incomes, tax data contain the most reliable income records but offer a limited range of socio-demographic variables essential for income analysis. In addition, information on the long-term evolution of the income distribution at the small-scale level is scarce. In this context, this thesis evaluates regional income inequality in Germany from various perspectives and embeds three self-contained studies in Chapters 3, 4, and 5, which present different data integration approaches. The first chapter motivates this thesis, while the second chapter provides a brief overview of the theoretical and empirical concepts as well as the datasets, highlighting the need to combine data from different sources. Chapter 3 tackles the issue of poor coverage of top incomes in surveys, also referred to as the ’missing rich’ problem, which leads to severe underestimation of income inequality. At the regional level this shortcoming is even more eminent due to small regional sample sizes. Based on reconciled tax and survey data, this chapter therefore proposes a new multiple imputation top income correction approach that, unlike previous research, focuses on the regional rather than the national level. The findings indicate that inequality between and within the regions is much larger than previously understood with the magnitude of the adjustment depending on the federal states’ level of inequality in the tail. To increase the potential of the tax data for income analysis and to overcome the lack of socio-demographic characteristics, Chapter 4 enriches the tax data with information on education and working time from survey data. For that purpose, a simulation study evaluates missing data methods and performant prediction models, finding that Multinomial Regression and Random Forest are the most suitable methods for the specific data fusion scenario. The results indicate that data fusion approaches broaden the scope for regional inequality analysis from cross-sectional enhanced tax data. Shifting from a cross-sectional to a longitudinal perspective on regional income inequality, Chapter 5 contributes to the currently relatively small body of literature dealing with the potential development of regional income disparities over time. Regionalized dynamic microsimulations provide a powerful tool for the study of long-term income developments. Therefore, this chapter extends the microsimulation model MikroSim with an income module that accounts for the individual, household, and regional context. On this basis, the potential dynamics in gender and migrant income gaps across the districts in Germany are simulated under scenarios of increased full-time employment rates and higher levels of tertiary education. The results show that the scenarios have regionally differing effects on inequality dynamics, highlighting the considerable potential of dynamic microsimulations for regional evidence-based policies. For the German case, the MikroSim model is well suited to analyze future regional developments and can be flexibly adapted for further specific research questions.

This thesis consists of four highly related chapters examining China’s rise in the aluminium industry. The first chapter addresses the conditions that allowed China, which first entered the market in the 1950s, to rise to world leadership in aluminium production. Although China was a latecomer, its re-entry into the market after the oil crises in the 1970s was a success and led to its ascent as the world’s largest aluminium producer by 2001. With an estimated production of 40.4 million tonnes in 2022, China represented almost 60% of the global output. Chapter 1 examines the factors underlying this success, such as the decline of international aluminium cartels, the introduction of innovative technology, the US granting China the MFN tariff status, Chinese-specific factors, and supportive government policies. Chapter 2 develops a mathematical model to analyze firms’ decisions in the short term. It examines how an incumbent with outdated technology and a new entrant with access to a new type of technology make strategic decisions, including the incumbent’s decision whether to deter entry, the production choice of firms, the optimal technology adoption rate of the newcomer, and cartel formation. Chapter 3 focuses on the adoption of new technology by firms upon market entry in four scenarios: firstly, a free market Cournot competition; secondly, a situation in which the government determines technology adoption rates; thirdly, a scenario in which the government controls both technology and production; and finally, a scenario where the government dictates technology adoption rates, production levels, and also the number of market participants. Chapter 4 applies the Spencer and Brander (1983) framework to examine strategic industrial policy. The model assumes that there are two exporting firms in two different countries that sell a product to a third country. We examine how the domestic firm is influenced by government intervention, such as the provision of a fixed-cost subsidy to improve its competitiveness relative to the foreign company. Chapter 4 initially investigates a scenario where only one government offers a fixed-cost subsidy, followed by an analysis of the case when both governments simultaneously provide financial help. Taken together, these chapters provide a comprehensive analysis of the strategic, technological, and political factors contributing to China’s leadership in the global aluminium industry. Chapter 1: The Rise of China as a Latecomer in the Global Aluminium Industry This chapter examines China’s remarkable transformation into a global leader in the aluminium industry, a sector in which the country accounted for approximately 58.9% of worldwide production in 2022. We examine how China, a latecomer to the aluminium industry that started off with labor-intensive technology in 1953, grew into the largest aluminium producer with some of the most advanced smelters in the world. This analysis identifies and discusses several opportunities that Chinese aluminium producers took advantage of. The first set of opportunities happened during the 1970s oil crises, which softened international competition and allowed China to acquire innovative smelting technology from Japan. The second set of opportunities started at about the same time when China opened its economy in 1978. The substantial demand for aluminium in China is influenced by both external and internal factors. Externally, the US granted China’s MFN tariff status in 1980 and China entered the World Trade Organization (WTO) in 2001. Both events contributed to a surge in Chinese aluminium consumption. Internally, China’s investment-led growth model boosted further its aluminium demand. Additional factors specific to China, such as low labor costs and the abundance of coal as an energy source, offer Chinese firms competitive advantages against international players. Furthermore, another window of opportunity is due to Chinese governmental policies, including phasing out old technology, providing subsidies, and gradually opening the economy to enhance domestic competition before expanding globally. By describing these elements, the study provides insights into the dynamic interplay of external circumstances and internal strategies that contributed to the success of the Chinese aluminium industry. Chapter 2: Technological Change and Strategic Choices for Incumbent and New Entrant This chapter introduces an oligopoly model that includes two actors: an incumbent and a potential entrant, that compete in the same market. We assume that two participants are located in different parts of the market: the incumbent is situated in area 1, whereas the potential entrant may venture into the other region, area 2. The incumbent exists in stage zero, where it can decide whether to deter the newcomer’s entry. A new type of technology exists in period one, when the newcomer may enter the market. In the short term, the incumbent is trapped with the outdated technology, while the new entrant may choose to partially or completely adopt the latest technology. Our results suggest the following: Firstly, the incumbent only tries to deter the new entrant if a condition for entry cost is met. Secondly, the new entrant is only interested in forming a cartel with the incumbent if a function of the ratio of the variable to new technology’s fixed-cost parameters is sufficiently high. Thirdly, if the newcomer asks to form a cartel, the incumbent will always accept this request. Finally, we can obtain the optimal new technology adoption rate for the newcomer. Chapter 3: Technological Adoption and Welfare in Cournot Oligopoly This study examines the difference between the optimal technology adoption rates chosen by firms in a homogeneous Cournot oligopoly and that preferred by a benevolent government upon firms’ market entry. To address the question of whether the technology choices of firms and government are similar, we analyze several different scenarios, which differ in the extent of government intervention in the market. Our results suggest a relationship between the number of firms in the market and the impact of government intervention on technology adoption rates. Especially in situations with a low number of firms that are interested in entering the market, greater government influence tends to lead to higher technology adoption rates of firms. Conversely, in scenarios with a higher number of firms and a government that lacks control over the number of market players, the technology adoption rate of firms will be highest when the government plays no role. Chapter 4: International Technological Innovation and Industrial Strategies Supporting domestic firms when they first enter the market may be seen as a favorable policy choice by governments around the world thanks to their ability to enhance the competitive advantage of domestic firms in non-cooperative competition against foreign enterprises (infant industry protection argument). This advantage may allow domestic firms to increase their market share and generate higher profits, thereby improving domestic welfare. This chapter utilizes the Spencer and Brander (1983) framework as a theoretical foundation to elucidate the effects of fixed-cost subsidies on firms’ production levels, technological innovations, and social welfare. The analysis examines two firms in different countries, each producing a homogeneous product that is sold in a third, separate country. We first examine the Cournot-Nash equilibrium in the absence of government intervention, followed by analyzing a scenario where just one government provides a financial subsidy for its domestic firm, and finally, we consider a situation where both governments simultaneously provide financial assistance for their respective firms. Our results suggest that governments aim to maximize social welfare by providing fixed-cost subsidies to their respective firms, finding themselves in a Chicken game scenario. Regarding technology innovation, subsidies lead to an increased technological adoption rate for recipient firms, regardless of whether one or both firms in a market receive support, compared to the situation without subsidies. The technology adoption rate of the recipient firm is higher than of its rival when only the recipient firm benefits from the fixed-cost subsidy. The lowest technology adoption rate of a firm occurs when the firm does not receive a fixed-cost subsidy, but its competitor does. Furthermore, global welfare will benefit the most in case when both exporting countries grant fixed-cost subsidies, and this welfare level is higher when only one country subsidizes than when no subsidies are provided by any country.

Sowohl national als auch international wird die zunehmende Digitalisierung von Prozessen gefordert. Die Heterogenität und Komplexität der dabei entstehenden Systeme erschwert die Partizipation für reguläre Nutzergruppen, welche zum Beispiel kein Expertenwissen in der Programmierung oder einen informationstechnischen Hintergrund aufweisen. Als Beispiel seien hier Smart Contracts genannt, deren Programmierung komplex ist und bei denen etwaige Fehler unmittelbar mit monetärem Verlust durch die direkte Verknüpfung der darunterliegenden Kryptowährung verbunden sind. Die vorliegende Arbeit stellt ein alternatives Protokoll für cyber-physische Verträge vor, das sich besonders gut für die menschliche Interaktion eignet und auch von regulären Nutzergruppen verstanden werden kann. Hierbei liegt der Fokus auf der Transparenz der Übereinkünfte und es wird weder eine Blockchain noch eine darauf beruhende digitale Währung verwendet. Entsprechend kann das Vertragsmodell der Arbeit als nachvollziehbare Verknüpfung zwischen zwei Parteien verstanden werden, welches die unterschiedlichen Systeme sicher miteinander verbindet und so die Selbstorganisation fördert. Diese Verbindung kann entweder computergestützt automatisch ablaufen, oder auch manuell durchgeführt werden. Im Gegensatz zu Smart Contracts können somit Prozesse Stück für Stück digitalisiert werden. Die Übereinkünfte selbst können zur Kommunikation, aber auch für rechtlich bindende Verträge genutzt werden. Die Arbeit ordnet das neue Konzept in verwandte Strömungen wie Ricardian oder Smart Contracts ein und definiert Ziele für das Protokoll, welche in Form der Referenzimplementierung umgesetzt werden. Sowohl das Protokoll als auch die Implementierung werden im Detail beschrieben und durch eine Erweiterung der Anwendung ergänzt, welche es Nutzenden in Regionen ohne direkte Internetverbindung ermöglicht, an ebenjenen Verträgen teilnehmen zu können. Weiterhin betrachtet die Evaluation die rechtlichen Rahmenbedinungen, die Übertragung des Protokolls auf Smart Contracts und die Performanz der Implementierung.

Physically-based distributed rainfall-runoff models as the standard analysis tools for hydro-logical processes have been used to simulate the water system in detail, which includes spa-tial patterns and temporal dynamics of hydrological variables and processes (Davison et al., 2015; Ek and Holtslag, 2004). In general, catchment models are parameterized with spatial information on soil, vegetation and topography. However, traditional approaches for eval-uation of the hydrological model performance are usually motivated with respect to dis-charge data alone. This may thus cloud model realism and hamper understanding of the catchment behavior. It is necessary to evaluate the model performance with respect to in-ternal hydrological processes within the catchment area as well as other components of wa-ter balance rather than runoff discharge at the catchment outlet only. In particular, a consid-erable amount of dynamics in a catchment occurs in the processes related to interactions of the water, soil and vegetation. Evapotranspiration process, for instance, is one of those key interactive elements, and the parameterization of soil and vegetation in water balance mod-eling strongly influences the simulation of evapotranspiration. Specifically, to parameterize the water flow in unsaturated soil zone, the functional relationships that describe the soil water retention and hydraulic conductivity characteristics are important. To define these functional relationships, Pedo-Transfer Functions (PTFs) are common to use in hydrologi-cal modeling. Opting the appropriate PTFs for the region under investigation is a crucial task in estimating the soil hydraulic parameters, but this choice in a hydrological model is often made arbitrary and without evaluating the spatial and temporal patterns of evapotran-spiration, soil moisture, and distribution and intensity of runoff processes. This may ulti-mately lead to implausible modeling results and possibly to incorrect decisions in regional water management. Therefore, the use of reliable evaluation approaches is continually re-quired to analyze the dynamics of the current interactive hydrological processes and predict the future changes in the water cycle, which eventually contributes to sustainable environ-mental planning and decisions in water management. Remarkable endeavors have been made in development of modelling tools that provide insights into the current and future of hydrological patterns in different scales and their im-pacts on the water resources and climate changes (Doell et al., 2014; Wood et al., 2011). Although, there is a need to consider a proper balance between parameter identifiability and the model's ability to realistically represent the response of the natural system. Neverthe-less, tackling this issue entails investigation of additional information, which usually has to be elaborately assembled, for instance, by mapping the dominant runoff generation pro-cesses in the intended area, or retrieving the spatial patterns of soil moisture and evapotran-spiration by using remote sensing methods, and evaluation at a scale commensurate with hydrological model (Koch et al., 2022; Zink et al., 2018). The present work therefore aims to give insights into the modeling approaches to simulate water balance and to improve the soil and vegetation parameterization scheme in the hydrological model subject to producing more reliable spatial and temporal patterns of evapotranspiration and runoff processes in the catchment. An important contribution to the overall body of work is a book chapter included among publications. The book chapter provides a comprehensive overview of the topic and valua-ble insights into the understanding the water balance and its estimation methods. Moreover, the first paper aimed to evaluate the hydrological model behavior with re-spect to contribution of various sources of information. To do so, a multi-criteria evaluation metric including soft and hard data was used to define constraints on outputs of the 1-D hydrological model WaSiM-ETH. Applying this evaluation metric, we could identify the optimal soil and vegetation parameter sets that resulted in a “behavioral” forest stand water balance model. It was found out that even if simulations of transpiration and soil water con-tent are consistent with measured data, but still the dominant runoff generation processes or total water balance might be wrongly calculated. Therefore, only using an evaluation scheme which looks over different sources of data and embraces an understanding of the local controls of water loss through soil and plant, allowed us to exclude the unrealistic modeling outputs. The results suggested that we may need to question the generally accept-ed soil parameterization procedures that apply default parameter sets. The second paper attempts to tackle the pointed model evaluation hindrance by getting down to the small-scale catchment (in Bavaria). Here, a methodology was introduced to analyze the sensitivity of the catchment water balance model to the choice of the Pedo-Transfer Functions (PTF). By varying the underlying PTFs in a calibrated and validated model, we could determine the resulting effects on the spatial distribution of soil hydraulic properties, total water balance in catchment outlet, and the spatial and temporal variation of the runoff components. Results revealed that the water distribution in the hydrologic system significantly differs amongst various PTFs. Moreover, the simulations of water balance components showed high sensitivity to the spatial distribution of soil hydraulic properties. Therefore, it was suggested that opting the PTFs in hydrological modeling should be care-fully tested by looking over the spatio-temporal distribution of simulated evapotranspira-tion and runoff generation processes, whether they are reasonably represented. To fulfill the previous studies’ suggestions, the third paper then aims to focus on evalu-ating the hydrological model through improving the spatial representation of dominant run-off processes. It was implemented in a mesoscale catchment in southwestern Germany us-ing the hydrological model WaSiM-ETH. Dealing with the issues of inadequate spatial ob-servations for rigorous spatial model evaluation, we made use of a reference soil hydrologic map available for the study area to discern the expected dominant runoff processes across a wide range of hydrological conditions. The model was parameterized by applying 11 PTFs and run by multiple synthetic rainfall events. To compare the simulated spatial patterns to the patterns derived by digital soil map, a multiple-component spatial performance metric (SPAEF) was applied. The simulated DRPs showed a large variability with regard to land use, topography, applied rainfall rates, and the different PTFs, which highly influence the rapid runoff generation under wet conditions. The three published manuscripts proceeded towards the model evaluation viewpoints that ultimately attain the behavioral model outputs. It was performed through obtaining information about internal hydrological processes that lead to certain model behaviors, and also about the function and sensitivity of some of the soil and vegetation parameters that may primarily influence those internal processes in a catchment. Accordingly, using this understanding on model reactions, and by setting multiple evaluation criteria, it was possi-ble to identify which parameterization could lead to behavioral model realization. This work, in fact, will contribute to solving some of the issues (e.g., spatial variability and modeling methods) identified as the 23 unsolved problems in hydrology in the 21st century (Blöschl et al., 2019). The results obtained in the present work encourage the further inves-tigations toward a comprehensive model calibration procedure considering multiple data sources simultaneously. This will enable developing the new perspectives to the current parameter estimation methods, which in essence, focus on reproducing the plausible dy-namics (spatio-temporal) of the other hydrological processes within the watershed.

This dissertation focusses on research into the personality construct of action vs. state orientation. Derived from the Personality-Systems-Interaction Theory (PSI Theory), state orientation is defined as a low ability to self-regulate emotions and associated with many adverse consequences – especially under stress. Because of the high prevalence of state orientation, it is a very important topic to investigate factors that help state-oriented people to buffer these adverse consequences. Action orientation, in contrast, is defined as a high ability to self-regulate own emotions in a very specific way: through accessing the self. The present dissertation demonstrates this theme in five studies, using a total of N = 1251 participants with a wide age range, encompassing different populations (students, non-student population (people from the coaching and therapy sector), applying different operationalisations to investigate self-access as a mediator or an outcome variable. Furthermore, it is tested whether the popular technique of mindfulness - that is advertised as a potent remedy for bringing people closer to the self -really works for everybody. The findings show that the presumed remedy is rather harmful for state-oriented individuals. Finally, an attempt to ameliorate these alienating effects, the present dissertation attempts to find theory-driven, and easy-to-apply solution how mindfulness exercises can be adapted.

Representation Learning techniques play a crucial role in a wide variety of Deep Learning applications. From Language Generation to Link Prediction on Graphs, learned numerical vector representations often build the foundation for numerous downstream tasks. In Natural Language Processing, word embeddings are contextualized and depend on their current context. This useful property reflects how words can have different meanings based on their neighboring words. In Knowledge Graph Embedding (KGE) approaches, static vector representations are still the dominant approach. While this is sufficient for applications where the underlying Knowledge Graph (KG) mainly stores static information, it becomes a disadvantage when dynamic entity behavior needs to be modelled. To address this issue, KGE approaches would need to model dynamic entities by incorporating situational and sequential context into the vector representations of entities. Analogous to contextualised word embeddings, this would allow entity embeddings to change depending on their history and current situational factors. Therefore, this thesis provides a description of how to transform static KGE approaches to contextualised dynamic approaches and how the specific characteristics of different dynamic scenarios are need to be taken into consideration. As a starting point, we conduct empirical studies that attempt to integrate sequential and situational context into static KG embeddings and investigate the limitations of the different approaches. In a second step, the identified limitations serve as guidance for developing a framework that enables KG embeddings to become truly dynamic, taking into account both the current situation and the past interactions of an entity. The two main contributions in this step are the introduction of the temporally contextualized Knowledge Graph formalism and the corresponding RETRA framework which realizes the contextualisation of entity embeddings. Finally, we demonstrate how situational contextualisation can be realized even in static environments, where all object entities are passive at all times. For this, we introduce a novel task that requires the combination of multiple context modalities and their integration with a KG based view on entity behavior.

Knowledge acquisition comprises various processes. Each of those has its dedicated research domain. Two examples are the relations between knowledge types and the influences of person-related variables. Furthermore, the transfer of knowledge is another crucial domain in educational research. I investigated these three processes through secondary analyses in this dissertation. Secondary analyses comply with the broadness of each field and yield the possibility of more general interpretations. The dissertation includes three meta-analyses: The first meta-analysis reports findings on the predictive relations between conceptual and procedural knowledge in mathematics in a cross-lagged panel model. The second meta-analysis focuses on the mediating effects of motivational constructs on the relationship between prior knowledge and knowledge after learning. The third meta-analysis deals with the effect of instructional methods in transfer interventions on knowledge transfer in school students. These three studies provide insights into the determinants and processes of knowledge acquisition and transfer. Knowledge types are interrelated; motivation mediates the relation between prior and later knowledge, and interventions influence knowledge transfer. The results are discussed by examining six key insights that build upon the three studies. Additionally, practical implications, as well as methodological and content-related ideas for further research, are provided.

Social entrepreneurship is a successful activity to solve social problems and economic challenges. Social entrepreneurship uses for-profit industry techniques and tools to build financially sound businesses that provide nonprofit services. Social entrepreneurial activities also lead to the achievement of sustainable development goals. However, due to the complex, hybrid nature of the business, social entrepreneurial activities are typically supported by macrolevel determinants. To expand our knowledge of how beneficial macro-level determinants can be, this work examines empirical evidence about the impact of macro-level determinants on social entrepreneurship. Another aim of this dissertation is to examine the impact at the micro level, as the growth ambitions of social and commercial entrepreneurs differ. At the beginning, the introductory section is explained in Chapter 1, which contains the motivation for the research, the research question, and the structure of the work. There is an ongoing debate about the origin and definition of social entrepreneurship. Therefore, the numerous phenomena of social entrepreneurship are examined theoretically in the previous literature. To determine the common consensus on the topic, Chapter 2 presents the theoretical foundations and definition of social entrepreneurship. The literature shows that a variety of determinants at the micro and macro levels are essential for the emergence of social entrepreneurship as a distinctive business model (Hartog & Hoogendoorn, 2011; Stephan et al., 2015; Hoogendoorn, 2016). It is impossible to create a society based on a social mission without the support of micro and macro-level-level determinants. This work examines the determinants and consequences of social entrepreneurship from different methodological perspectives. The theoretical foundations of the micro- and macro-level determinants influencing social entrepreneurial activities were discussed in Chapter 3. The purpose of reproducibility in research is to confirm previously published results (Hubbard et al., 1998; Aguinis & Solarino, 2019). However, due to the lack of data, lack of transparency of methodology, reluctance to publish, and lack of interest from researchers, there is a lack of promoting replication of the existing research study (Baker, 2016; Hedges & Schauer, 2019a). Promoting replication studies has been regularly emphasized in the business and management literature (Kerr et al., 2016; Camerer et al., 2016). However, studies that provide replicability of the reported results are considered rare in previous research (Burman et al., 2010; Ryan & Tipu, 2022). Based on the research of Köhler and Cortina (2019), an empirical study on this topic is carried out in Chapter 4 of this work. Given this focus, researchers have published a large body of research on the impact of microand macro-level determinants on social inclusion, although it is still unclear whether these studies accurately reflect reality. It is important to provide conceptual underpinnings to the field through a reassessment of published results (Bettis et al., 2016). The results of their research make it abundantly clear that the macro determinants support social entrepreneurship. In keeping with the more narrative approach, which is a crucial concern and requires attention, Chapter 5 considered the reproducibility of previous results, particularly on the topic of social entrepreneurship. We replicated the results of Stephan et al. (2015) to establish the trend of reproducibility and validate the specific conclusions they drew. The literal and constructive replication in the dissertation inspired us to explore technical replication research on social entrepreneurship. Chapter 6 evaluates the fundamental characteristics that have proven to be key factors in the growth of social ventures. The current debate reviews and references literature that has specifically focused on the development of social entrepreneurship. An empirical analysis of factors directly related to the ambitious growth of social entrepreneurship is also carried out. Numerous social entrepreneurial groups have been studied concerning this association. Chapter 6 compares the growth ambitions of social and traditional (commercial) entrepreneurship as consequences at the micro level. This study examined many characteristics of social and commercial entrepreneurs' growth ambitions. Scholars have claimed to some extent that the growth of social entrepreneurship differs from commercial entrepreneurial activities due to objectivity differences (Lumpkin et al., 2013; Garrido-Skurkowicz et al., 2022). Qualitative research has been used in studies to support the evidence on related topics, including Gupta et al (2020) emphasized that research needs to focus on specific concepts of social entrepreneurship for the field to advance. Therefore, this study provides a quantitative, analysis-based assessment of facts and data. For this purpose, a data set from the Global Entrepreneurship Monitor (GEM) 2015 was used, which examined 12,695 entrepreneurs from 38 countries. Furthermore, this work conducted a regression analysis to evaluate the influence of various social and commercial characteristics of entrepreneurship on economic growth in developing countries. Chapter 7 briefly explains future directions and practical/theoretical implications.

This thesis contains four parts that are all connected by their contributions to the Efficient Market Hypothesis and decision-making literature. Chapter two investigates how national stock market indices reacted to the news of national lockdown restrictions in the period from January to May 2020. The results show that lockdown restrictions led to different reactions in a sample of OECD and BRICS countries: there was a general negative effect resulting from the increase in lockdown restrictions, but the study finds strong evidence for underreaction during the lockdown announcement, followed by some overreaction that is corrected subsequently. This under-/overreaction pattern, however, is observed mostly during the first half of our time series, pointing to learning effects. Relaxation of the lockdown restrictions, on the other hand, had a positive effect on markets only during the second half of our sample, while for the first half of the sample, the effect was negative. The third chapter investigates the gender differences in stock selection preferences on the Taiwan Stock Exchange. By utilizing trading data from the Taiwan Stock Exchange over a span of six years, it becomes possible to analyze trading behavior while minimizing the self-selection bias that is typically present in brokerage data. To study gender differences, this study uses firm-level data. The percentage of male traders in a company is the dependent variable, while the company’s industry and fundamental/technical aspects serve as independent variables. The results show that the percentage of women trading a company rises with a company’s age, market capitalization, a company’s systematic risk, and return. Men trade more frequently and show a preference for dividend-paying stocks and for industries with which they are more familiar. The fourth chapter investigated the relationship between regret and malicious and benign envy. The relationship is analyzed in two different studies. In experiment 1, subjects had to fill out psychological scales that measured regret, the two types of envy, core self-evaluation and the big 5 personality traits. In experiment 2, felt regret is measured in a hypothetical scenario, and the subject’s felt regret was regressed on the other variables mentioned above. The two experiments revealed that there is a positive direct relationship between regret and benign envy. The relationship between regret and malicious envy, on the other hand, is mostly an artifact of core self-evaluation and personality influencing both malicious envy and regret. The relationship can be explained by the common action tendency of self-improvement for regret and benign envy. Chapter five discusses the differences in green finance regulation and implementation between the EU and China. China introduced the Green Silk Road, while the EU adopted the Green Deal and started working with its own green taxonomy. The first difference comes from the definition of green finance, particularly with regard to coal-fired power plants. Especially the responsibility of nation-states’ emissions abroad. China is promoting fossil fuel projects abroad through its Belt and Road Initiative, but the EU’s Green Deal does not permit such actions. Furthermore, there are policies in both the EU and China that create contradictory incentives for economic actors. On the one hand, the EU and China are improving the framework conditions for green financing while, on the other hand, still allowing the promotion of conventional fuels. The role of central banks is also different between the EU and China. China’s central bank is actively working towards aligning the financial sector with green finance. A possible new role of the EU central bank or the priority financing of green sectors through political decision-making is still being debated.

Nachdem er in den 1750er und 1760er Jahren graphische Bildsatiren zu aktuellen innen- und außenpolitischen Themen veröffentlich hatte, wurde William Hogarth selbst in zahlreichen Karikaturen verspottet und verleumdet. Ausgehend von dieser Beobachtung fragt die vorliegende Dissertation, welche Haltung sich den politischen Blättern des Künstlers entnehmen lässt und mit welchen künstlerischen Mitteln er dieser Ausdruck verlieh. Durch Analyse der politischen Ikonographie lassen sich die Themen und Akteure beschreiben. Mit der rezeptionsästhetischen Methode unter Hinzunahme der Sprech- und Bildakttheorie und der Propaganda Studies werden ihre tendenziösen Aussagen und manipulative Absichten entschlüsselt. In ihrer Regierungsaffinität unterscheidet sich Hogarths politische Kunst maßgeblich von der oppositionellen Bildsatire Londons. Die Differenz spiegelt sich v. a. in den persönlichen Angriffen, mit denen zeitgenössische Satiriker Hogarth kritisierten. Als erstes reagierte Paul Sandby („The Painter’s March from Finchly“, 1753) auf Hogarths Darstellung des Jakobitischen Aufstandes 1745, womit er eine Begründung für die von William Augustus, Duke of Cumberland angestrebte Militärreform lieferte („March of the Guards to Finchley“, 1751); Für seine Gin Act-Kampagne („Gin Lane“ und „Beer Street“, 1750/51) erweiterte er die Pro-Gin-Ikonographie der 1730er Jahre (Anonymous: „The lamentable Fall of Madam Geneva”, 1736, Anonymous: „To those melancholly Sufferers the Destillers […] The Funeral Procession of Madam Geneva“, 1751), um sich für die staatliche Reglementierung der Destillen auszusprechen. In seinen Publikationen zum Siebenjährigen Krieg, mit denen er die Politik der jeweiligen Regierungen unter Thomas Pellham-Holles, Duke of Newcastle und William Pitt (the Elder) („The Invasion“, 1756) oder John Stuart, Earl of Bute („The Times Pl. 1“, 1763) unterstützte, zeigt sich Hogarths Opportunismus. Letztlich wurde seine Fürsprache für die unbeliebte Tory-Regierung und seine Kritik an William Pitt Anlass für Hogarths Herabwürdigung durch die Whig-treue Satire. Nach diesem Bruch publizierten beide Seiten verunglimpfende Portraitkarikaturen, die auf Rufmord des Gegners durch Kriminalisierung, Deformation und Dämonisierung setzten (William Hogarth: „John Wilkes Esqr.“, 1763, Anonymous „Tit for Tat“, 1763, Anonymous: „An Answer to the Print of John Wilkes Esqr. by WM Hogarth“, 1763, Anonymous: „Pug the snarling cur chastised Or a Cure for the Mange“, 1763). Die Bildvergleiche zwischen Hogarths politischen Werken und den Reaktionen, die sie hervorriefen, zeigen, dass der Unterschied nicht im Bildgegenstand oder der politischen Ikonographie liegt, sondern in der Ausrichtung ihrer politischen Einflussnahme. Dabei ist vor allem Hogarths regierungsloyale Haltung hervorzuheben. Folglich muss die Forschungsmeinung von einer grundsätzlich kritischen Haltung Hogarths redigiert werden, da er sich nachweislich konservativ positioniert und dem Regierungshandeln und Machterhalt der Eliten Vorschub leistete. Das vorliegende Dissertationsvorhaben untersucht die propagandistische Qualität der Werke Hogarths im Vergleich zu den zeitgenössischen Satirikern und macht die unterschiedliche politische Stoßrichtung sichtbar. Aufschluss gibt dabei die Anwendung künstlerischer und karikaturesker Mittel (das „Wie“) zum Zweck der burlesque (Posse/Parodie), des ridicule (Lächerlichmachung/Spott) bis bin zur Agitation, sowohl in Hogarths Werken als auch in den Karikaturen, die gegen ihn gerichtet waren. Da William Hogarth diese Stilmittel maßgeblich prägte und ihre Entwicklung forcierte, werden sie in der vorliegenden Arbeit unter dem Begriff Hogarthian Wit summiert. Mithilfe der Methode und Begriffe der Propaganda Studies lassen sich Intention und Zweck (das „Was“) als Bildakte beschreiben: Während es sich bei den Werken grundsätzlich um bias handelte, die basierend auf einer Ideologie die öffentliche Meinung beeinflusste, nahm ihre Schlagkraft in den 1760er Jahren stark zu; auf verrätselte Stellungnahmen folgte persönliche und offene Kritik an öffentlichen Personen, bis hin zum Rufmord. Dabei rezipierten sich die Künstler gegenseitig und bildeten Thesen und Antithesen aus. Hogarths einseitige Darstellungen wurden korrigiert und ergänzt, seine politische Kunst als Propaganda enttarnt. Schließlich wurden ihm Lügen und üble Nachrede vorgeworfen. Indem sie ihn anklagten oder durch Sekundärstigmatisierung eine Bestrafung in effigie vornahmen, forderten die Werke vom Rezipienten ein strafendes Urteil. Zu den künstlerischen Mitteln, die dabei zur Anwendung kommen, gehören eine politische Ikonographie und stereotype Feindbilder sowie nationale Konstruktionen, rezeptionsästhetische Mittel wie Juxtapositionen, Rezeptions- und Identifikationsfiguren sowie rhetorische und Mittel des Sprechakts, bis hin zu Perlokutionen. Die Werke lassen sich als Propaganda und somit als hierarchische Kommunikation beschreiben, die manipulative Bildstrategien nutzten, welche nicht nur der Beeinflussung der öffentlichen Meinung dienten, sondern politische Handlungen forcierten. Bezeichnend ist, dass beide Seiten dieselben Ikonographie, Stil-, Kompositions- und Kommunikationsmittel anwendeten, unabhängig von ihrer politischen Aussage, wodurch der Hogarthian Wit gefestigt und stetig weiterentwickelt wurde.

When humans encounter attitude objects (e.g., other people, objects, or constructs), they evaluate them. Often, these evaluations are based on attitudes. Whereas most research focuses on univalent (i.e., only positive or only negative) attitude formation, little research exists on ambivalent (i.e., simultaneously positive and negative) attitude formation. Following a general introduction into ambivalence, I present three original manuscripts investigating ambivalent attitude formation. The first manuscript addresses ambivalent attitude formation from previously univalent attitudes. The results indicate that responding to a univalent attitude object incongruently leads to ambivalence measured via mouse tracking but not ambivalence measured via self-report. The second manuscript addresses whether the same number of positive and negative statements presented block-wise in an impression formation task leads to ambivalence. The third manuscript also used an impression formation task and addresses the question of whether randomly presenting the same number of positive and negative statements leads to ambivalence. Additionally, the effect of block size of the same valent statements is investigated. The results of the last two manuscripts indicate that presenting all statements of one valence and then all statements of the opposite valence leads to ambivalence measured via self-report and mouse tracking. Finally, I discuss implications for attitude theory and research as well as future research directions.

This dissertation examines the relevance of regimes for stock markets. In three research articles, we cover the identification and predictability of regimes and their relationships to macroeconomic and financial variables in the United States. The initial two chapters contribute to the debate on the predictability of stock markets. While various approaches can demonstrate in-sample predictability, their predictive power diminishes substantially in out-of-sample studies. Parameter instability and model uncertainty are the primary challenges. However, certain methods have demonstrated efficacy in addressing these issues. In Chapter 1 and 2, we present frameworks that combine these methods meaningfully. Chapter 3 focuses on the role of regimes in explaining macro-financial relationships and examines the state-dependent effects of macroeconomic expectations on cross-sectional stock returns. Although it is common to capture the variation in stock returns using factor models, their macroeconomic risk sources are unclear. According to macro-financial asset pricing, expectations about state variables may be viable candidates to explain these sources. We examine their usefulness in explaining factor premia and assess their suitability for pricing stock portfolios. In summary, this dissertation improves our understanding of stock market regimes in three ways. First, we show that it is worthwhile to exploit the regime dependence of stock markets. Markov-switching models and their extensions are valuable tools for filtering the stock market dynamics and identifying and predicting regimes in real-time. Moreover, accounting for regime-dependent relationships helps to examine the dynamic impact of macroeconomic shocks on stock returns. Second, we emphasize the usefulness of macro-financial variables for the stock market. Regime identification and forecasting benefit from their inclusion. This is particularly true in periods of high uncertainty when information processing in financial markets is less efficient. Finally, we recommend to address parameter instability, estimation risk, and model uncertainty in empirical models. Because it is difficult to find a single approach that meets all of these challenges simultaneously, it is advisable to combine appropriate methods in a meaningful way. The framework should be as complex as necessary but as parsimonious as possible to mitigate additional estimation risk. This is especially recommended when working with financial market data with a typically low signal-to-noise ratio.

Partial differential equations are not always suited to model all physical phenomena, especially, if long-range interactions are involved or if the actual solution might not satisfy the regularity requirements associated with the partial differential equation. One remedy to this problem are nonlocal operators, which typically consist of integrals that incorporate interactions between two separated points in space and the corresponding solutions to nonlocal equations have to satisfy less regularity conditions. In PDE-constrained shape optimization the goal is to minimize or maximize an objective functional that is dependent on the shape of a certain domain and on the solution to a partial differential equation, which is usually also influenced by the shape of this domain. Moreover, parameters associated with the nonlocal model are oftentimes domain dependent and thus it is a natural next step to now consider shape optimization problems that are governed by nonlocal equations. Therefore, an interface identification problem constrained by nonlocal equations is thoroughly investigated in this thesis. Here, we focus on rigorously developing the first and second shape derivative of the associated reduced functional. In addition, we study first- and second-order shape optimization algorithms in multiple numerical experiments. Moreover, we also propose Schwarz methods for nonlocal Dirichlet problems as well as regularized nonlocal Neumann problems. Particularly, we investigate the convergence of the multiplicative Schwarz approach and we conduct a number of numerical experiments, which illustrate various aspects of the Schwarz method applied to nonlocal equations. Since applying the finite element method to solve nonlocal problems numerically can be quite costly, Local-to-Nonlocal couplings emerged, which combine the accuracy of nonlocal models on one part of the domain with the fast computation of partial differential equations on the remaining area. Therefore, we also examine the interface identification problem governed by an energy-based Local-to-Nonlocal coupling, which can be numerically computed by making use of the Schwarz method. Here, we again present a formula for the shape derivative of the associated reduced functional and investigate a gradient based shape optimization method.

The gender wage gap in labor market outcomes has been intensively investigated for decades, yet it remains a relevant and innovative research topic in labor economics. Chapter 2 of this dissertation explores the pressing issue of gender wage disparity in Ethiopia. By applying various empirical methodologies and measures of occupational segregation, this chapter aims to analyze the role of female occupational segregation in explaining the gender wage gap across the pay distribution. The findings reveal a significant difference in monthly wages, with women consistently earning lower wages across the wage distribution. Importantly, the result indicates a negative association between female occupational segregation and the average earnings of both men and women. Furthermore, the estimation result shows that female occupational segregation partially explains the gender wage gap at the bottom of the wage distribution. I find that the magnitude of the gender wage gap in the private sector is higher than in the public sector. In Chapter 3, the Ethiopian Demography and Health Survey data are leveraged to explore the causal relationship between female labor force participation and domestic violence. Domestic violence against women is a pervasive public health concern, particularly in Africa, including Ethiopia, where a significant proportion of women endure various forms of domestic violence perpetrated by intimate partners. Economic empowerment of women through increased participation in the labor market can be one of the mechanisms for mitigating the risk of domestic violence. This study seeks to provide empirical evidence supporting this hypothesis. Using the employment rate of women at the community level as an instrumental variable, the finding suggests that employment significantly reduces the risk of domestic violence against women. More precisely, the result shows that women’s employment status significantly reduces domestic violence by about 15 percentage points. This finding is robust for different dimensions of domestic violence, such as physical, sexual, and emotional violence. By examining the employment outcomes of immigrants in the labor market, Chapter 4 extends the dissertation's inquiry to the dynamics of immigrant economic integration into the destination country. Drawing on data from the German Socio-Economic Panel, the chapter scrutinizes the employment gap between native-born individuals and two distinct groups of first-generation immigrants: refugees and other migrants. Through rigorous analysis, Chapter 4 aims to identify the factors contributing to disparities in employment outcomes among these groups. In this chapter, I aim to disentangle the heterogeneity characteristic of refugees and other immigrants in the labor market, thereby contributing to a deeper understanding of immigrant labor market integration in Germany. The results show that refugees and other migrants are less likely to find employment than comparable natives. The refugee-native employment gap is much wider than other migrant-native employment gap. Moreover, the findings vary by gender and migration categories. While other migrant men do not differ from native men in the probability of being employed, refugee women are the most disadvantaged group compared to other migrant women and native women in the probability of being employed. The study suggests that German language proficiency and permanent resident permits partially explain the lower employment probability of refugees in the German labor market. Chapter 5 (co-authored with Uwe Jirjahn) utilizes the same dataset to explore the immigrant-native trade union membership gap, focusing on the role of integration in the workplace and into society. The integration of immigrants into society and the workplace is vital not only to improve migrant's performance in the labor market but also to actively participate in institutions such as trade unions. In this study, we argue that the incomplete integration of immigrants into the workplace and society implies that immigrants are less likely to be union members than natives. Our findings show that first-generation immigrants are less likely to be trade union members than natives. Notably, the analysis shows that the immigrant-native gap in union membership depends on immigrants’ integration into the workplace and society. The gap is smaller for immigrants working in firms with a works council and having social contacts with Germans. Moreover, the results reveal that the immigrant-native union membership gap is decreasing in the year since arrival in Germany.

This thesis deals with consumption-investment allocation problems with Epstein-Zin recursive utility, building upon the dualization procedure introduced by [Matoussi and Xing, 2018]. While their work exclusively focuses on truly recursive utility, we extend their procedure to include time-additive utility using results from general convex analysis. The dual problem is expressed in terms of a backward stochastic differential equation (BSDE), for which existence and uniqueness results are established. In this regard, we close a gap left open in previous works, by extending results restricted to specific subsets of parameters to cover all parameter constellations within our duality setting. Using duality theory, we analyze the utility loss of an investor with recursive preferences, that is, her difference in utility between acting suboptimally in a given market, compared to her best possible (optimal) consumption-investment behaviour. In particular, we derive universal power utility bounds, presenting a novel and tractable approximation of the investors’ optimal utility and her welfare loss associated to specific investment-consumption choices. To address quantitative shortcomings of those power utility bounds, we additionally introduce one-sided variational bounds that offer a more effective approximation for recursive utilities. The theoretical value of our power utility bounds is demonstrated through their application in a new existence and uniqueness result for the BSDE characterizing the dual problem. Moreover, we propose two approximation approaches for consumption-investment optimization problems with Epstein-Zin recursive preferences. The first approach directly formalizes the classical concept of least favorable completion, providing an analytic approximation fully characterized by a system of ordinary differential equations. In the special case of power utility, this approach can be interpreted as a variation of the well-known Campbell-Shiller approximation, improving some of its qualitative shortcomings with respect to state dependence of the resulting approximate strategies. The second approach introduces a PDE-iteration scheme, by reinterpreting artificial completion as a dynamic game, where the investor and a dual opponent interact until reaching an equilibrium that corresponds to an approximate solution of the investors optimization problem. Despite the need for additional approximations within each iteration, this scheme is shown to be quantitatively and qualitatively accurate. Moreover, it is capable of approximating high dimensional optimization problems, essentially avoiding the curse of dimensionality and providing analytical results.

Einige Forschungsergebnisse zeigen, dass emotionale Empfindungen kognitive Bereiche beeinflussen oder mit diesen im Zusammenhang stehen. Aufbauend auf den Ergebnissen wurden zwei Studien konzipiert. In Studie 1 wurde der Zusammenhang zwischen den Valenzen der dispositionalen emotionalen Empfindungen und der globalen Selbstbewertung des Gedächtnisses (Metagedächtnis) bei Lehramtsstudierenden (N = 218) untersucht. Die dispositionalen Empfindungen wurden mittels des deutschen Positive and Negativ Affect Schedule (PANAS) (Krohne, Egloff, Kohlmann & Tausch, 1996) und die globale Selbstbewertung des Gedächtnisses mit dem deutschen Squire Subjective Memory Questionnaire (SSMQ) (Wolf, 2017) erfasst. Angenommen wurde, dass die positive Valenz im Gegensatz zu der negativen Valenz im positiven Zusammenhang mit der höheren Gedächtniseinschätzung stehen. Die Ergebnisse bestätigen die Hypothesen. In Studie 2 wurde die aktuelle Valenz mittels des Open Affective Standardized Image Set (OASIS) (Kurdi, Lozano & Banaji, 2017) induziert, um Veränderungen des Metagedächtnisses und der tatsächlichen Gedächtnisleistung bei Lehramtsstudierenden (N = 44) zu untersuchen. Angenommen wurde, dass die positive Valenz positiv, die negative Valenz negativ und die neutrale Valenz nicht auf das Metagedächtnis und die Gedächtnisleistung wirkt. Weitere Zusammenhänge zwischen dem Metagedächtnis und der Gedächtnisleistung sowie der induzierten Valenz und der Gedächtnisleistung wurden angenommen. Die Messinstrumente aus Studie 1 blieben dieselben. Die Gedächtnisleistung wurde mittels eines sinnarmen Silbentests nach Ebbinghaus (1885) operationalisiert. Die Ergebnisse bestätigen die Hypothesen nicht. Die Emotionsinduktion hatte keinen Erfolg. Die Ergebnisse können damit nicht auf eine veränderte Valenz bezogen werden. Wie in Studie 1 zeigte sich ein Zusammenhang zwischen den dispositionalen Empfindungen und dem Metagedächtnis. Weitere explorative Ergebnisse, vor allem im Bezug auf das Geschlecht, wurden dargestellt. Die Ergebnisse sind bedeutsam für die Professionalisierung von Lehramtsstudierenden.

The goal of this work is to compare operators that are defined on probably varying Hilbert spaces. Distance concepts for operators as well as convergence concepts for such operators are explained and examined. For distance concepts we present three main notions. All have in common that they use space-linking operators that connect the spaces. At first, we look at unitary maps and compare the unitary orbits of the operators. Then, we consider isometric embeddings, which is based on a concept of Joachim Weidmann. Then we look at contractions but with more norm equations in comparison. The latter idea is based on a concept of Olaf Post called quasi-unitary equivalence. Our main result is that the unitary and isometric distances are equal provided the operators are both self-adjoint and have 0 in their essential spectra. In the third chapter, we focus specifically on the investigation of these distance terms for compact operators or operators in p-Schatten classes. In this case, the interpretation of the spectra as null sequences allows further distance investigation. Chapter four deals mainly with convergence terms of operators on varying Hilbert spaces. The analyses in this work deal exclusively with concepts of norm resolvent convergence. The main conclusion of the chapter is that the generalisation for norm resolvent convergence of Joachim Weidmann and the generalisation of Olaf Post, called quasi-unitary equivalence, are equivalent to each other. In addition, we specify error bounds and deal with the convergence speed of both concepts. Two important implications of these convergence notions are that the approximation is spectrally exact, i.e., the spectra converge suitably, and that the convergence is transferred to the functional calculus of the bounded functions vanishing at infinity.

Although universality has fascinated over the last decades, there are still numerous open questions in this field that require further investigation. In this work, we will mainly focus on classes of functions whose Fourier series are universal in the sense that they allow us to approximate uniformly any continuous function defined on a suitable subset of the unit circle. The structure of this thesis is as follows. In the first chapter, we will initially introduce the most important notation which is needed for our following discussion. Subsequently, after recalling the notion of universality in a general context, we will revisit significant results concerning universality of Taylor series. The focus here is particularly on universality with respect to uniform convergence and convergence in measure. By a result of Menshov, we will transition to universality of Fourier series which is the central object of study in this work. In the second chapter, we recall spaces of holomorphic functions which are characterized by the growth of their coefficients. In this context, we will derive a relationship to functions on the unit circle via an application of the Fourier transform. In the second part of the chapter, our attention is devoted to the $\mathcal{D}_{\textup{harm}}^p$ spaces which can be viewed as the set of harmonic functions contained in the $W^{1,p}(\D)$ Sobolev spaces. In this context, we will also recall the Bergman projection. Thanks to the intensive study of the latter in relation to Sobolev spaces, we can derive a decomposition of $\mathcal{D}_{\textup{harm}}^p$ spaces which may be seen as analogous to the Riesz projection for $L^p$ spaces. Owing to this result, we are able to provide a link between $\mathcal{D}_{\textup{harm}}^p$ spaces and spaces of holomorphic functions on $\mathbb{C}_\infty \setminus \s$ which turns out to be a crucial step in determining the dual of $\mathcal{D}_{\textup{harm}}^p$ spaces. The last section of this chapter deals with the Cauchy dual which has a close connection to the Fantappié transform. As an application, we will determine the Cauchy dual of the spaces $D_\alpha$ and $D_{\textup{harm}}^p$, two results that will prove to be very helpful later on. Finally, we will provide a useful criterion that establishes a connection between the density of a set in the direct sum $X \oplus Y$ and the Cauchy dual of the intersection of the respective spaces. The subsequent chapter will delve into the theory of capacities and, consequently, potential theory which will prove to be essential in formulating our universality results. In addition to introducing further necessary terminologies, we will define capacities in the first section following [16], however in the frame of separable metric spaces, and revisit the most important results about them. Simultaneously, we make preparations that allow us to define the $\mathrm{Li}_\alpha$-capacity which will turn out to be equivalent to the classical Riesz $\alpha$-capacity. The $\mathrm{Li}_\alpha$-capacity proves to be more adapted to the $D_\alpha$ spaces. It becomes apparent in the course of our discussion that the $\mathrm{Li}_\alpha$-capacity is essential to prove uniqueness results for the class $D_\alpha$. This leads to the centerpiece of this chapter which forms the energy formula for the $\mathrm{Li}_\alpha$-capacity on the unit circle. More precisely, this identity establishes a connection between the energy of a measure and its corresponding Fourier coefficients. We will briefly deal with the complement-equivalence of capacities before we revisit the concept of Bessel and Riesz capacities, this time, however, in a much more general context, where we will mainly rely on [1]. Since we defined capacities on separable metric spaces in the first section, we can draw a connection between Bessel capacities and $\mathrm{Li}_\alpha$-capacities. To conclude this chapter, we would like to take a closer look at the geometric meaning of capacities. Here, we will point out a connection between the Hausdorff dimension and the polarity of a set, and transfer it to the $\mathrm{Li}_\alpha$-capacity. Another aspect will be the comparison of Bessel capacities across different dimensions, in which the theory of Wolff potentials crystallizes as a crucial auxiliary tool. In the fourth chapter of this thesis, we will turn our focus to the theory of sets of uniqueness, a subject within the broader field of harmonic analysis. This theory has a close relationship with sets of universality, a connection that will be further elucidated in the upcoming chapter. The initial section of this chapter will be dedicated to the notion of sets of uniqueness that is specifically adapted to our current context. Building on this concept, we will recall some of the fundamental results of this theory. In the subsequent section, we will primarily rely on techniques from previous chapters to determine the closed sets of uniqueness for the class $\mathcal{D}_{\alpha}$. The proofs we will discuss are largely influenced by [16, p.\ 178] and [9, pp.\ 82]. One more time, it will become evident that the introduction of the $\mathrm{Li}_\alpha$-capacity in the third chapter and the closely associated energy formula on the unit circle, were the pivotal factors that enabled us to carry out these proofs. In the final chapter of our discourse, we will present our results on universality. To begin, we will recall a version of the universality criterion which traces back to the work of Grosse-Erdmann (see [26]). Coupled with an outcome from the second chapter, we will prove a result that allows us to obtain the universality of a class using the technique of simultaneous approximation. This tool will play a key role in the proof of our universality results which will follow hereafter. Our attention will first be directed toward the class $D_\alpha$ with $\alpha$ in the interval $(0,1]$. Here, we summarize that universality with respect to uniform convergence occurs on closed and $\alpha$-polar sets $E \subset \s$. Thanks to results of Carleson and further considerations, which particularly rely on the favorable behavior of the $\mathrm{Li}_\alpha$-kernel, we also find that this result is sharp. In particular, it may be seen as a generalization of the universality result for the harmonic Dirichlet space. Following this, we will investigate the same class, however, this time for $\alpha \in [-1,0)$. In this case, it turns out that universality with respect to uniform convergence occurs on closed and $(-\alpha)$-complement-polar sets $E \subset \s$. In particular, these sets of universality can have positive arc measure. In the final section, we will focus on the class $D_{\textup{harm}}^p$. Here, we manage to prove that universality occurs on closed and $(1,p)$-polar sets $E \subset \s$. Through results of Twomey [68] combined with an observation by Girela and Pélaez [23], as well as the decomposition of $D_{\textup{harm}}^p$, we can deduce that the closed sets of universality with respect to uniform convergence of the class $D_{\textup{harm}}^p$ are characterized by $(1,p)$-polarity. We conclude our work with an application of the latter result to the class $D^p$. We will show that the closed sets of divergence for the class $D^p$ are given by the $(1,p)$-polar sets.

This dissertation addresses the measurement and evaluation of the energy and resource efficiency of software systems. Studies show that the environmental impact of Information and Communications Technologies (ICT) is steadily increasing and is already estimated to be responsible for 3 % of the total greenhouse gas (GHG) emissions. Although it is the hardware that consumes natural resources and energy through its production, use, and disposal, software controls the hardware and therefore has a considerable influence on the used capacities. Accordingly, it should also be attributed a share of the environmental impact. To address this softwareinduced impact, the focus is on the continued development of a measurement and assessment model for energy and resource-efficient software. Furthermore, measurement and assessment methods from international research and practitioner communities were compared in order to develop a generic reference model for software resource and energy measurements. The next step was to derive a methodology and to define and operationalize criteria for evaluating and improving the environmental impact of software products. In addition, a key objective is to transfer the developed methodology and models to software systems that cause high consumption or offer optimization potential through economies of scale. These include, e. g., Cyber-Physical Systems (CPS) and mobile apps, as well as applications with high demands on computing power or data volumes, such as distributed systems and especially Artificial Intelligence (AI) systems. In particular, factors influencing the consumption of software along its life cycle are considered. These factors include the location (cloud, edge, embedded) where the computing and storage services are provided, the role of the stakeholders, application scenarios, the configuration of the systems, the used data, its representation and transmission, or the design of the software architecture. Based on existing literature and previous experiments, distinct use cases were selected that address these factors. Comparative use cases include the implementation of a scenario in different programming languages, using varying algorithms, libraries, data structures, protocols, model topologies, hardware and software setups, etc. From the selection, experimental scenarios were devised for the use cases to compare the methods to be analyzed. During their execution, the energy and resource consumption was measured, and the results were assessed. Subtracting baseline measurements of the hardware setup without the software running from the scenario measurements makes the software-induced consumption measurable and thus transparent. Comparing the scenario measurements with each other allows the identification of the more energyefficient setup for the use case and, in turn, the improvement/optimization of the system as a whole. The calculated metrics were then also structured as indicators in a criteria catalog. These indicators represent empirically determinable variables that provide information about a matter that cannot be measured directly, such as the environmental impact of the software. Together with verification criteria that must be complied with and confirmed by the producers of the software, this creates a model with which the comparability of software systems can be established. The gained knowledge from the experiments and assessments can then be used to forecast and optimize the energy and resource efficiency of software products. This enables developers, but also students, scientists and all other stakeholders involved in the life cycleof software, to continuously monitor and optimize the impact of their software on energy and resource consumption. The developed models, methods, and criteria were evaluated and validated by the scientific community at conferences and workshops. The central outcomes of this thesis, including a measurement reference model and the criteria catalog, were disseminated in academic journals. Furthermore, the transfer to society has been driven forward, e. g., through the publication of two book chapters, the development and presentation of exemplary best practices at developer conferences, collaboration with industry, and the establishment of the eco-label “Blue Angel” for resource and energy-efficient software products. In the long term, the objective is to effect a change in societal attitudes and ultimately to achieve significant resource savings through economies of scale by applying the methods in the development of software in general and AI systems in particular.

Biodiversity is threatened by a wide range of anthropogenic activities. Monitoring offers critical insights into how and why biodiversity is changing, helping to identify effective measures for maintaining biodiversity and its ecosystem services. However, conventional biodiversity monitoring methods are labor-intensive, and standardized long-term monitoring series are scarce. DNA-based approaches like metabarcoding environmental DNA (eDNA) promise rapid, cost-efficient, and highly resolved community data. At the same time, scientists are looking for alternative data sources that can compensate for the lack of long-term monitoring data to study past biodiversity changes. This work explores the potential of the German Environmental Specimen Bank (ESB), a pollution monitoring archive, which appears particularly promising for retrospective biodiversity monitoring. Biota samples from different ecosystems across the country are collected and archived at an exceptional level of standardization. Sampling species act as natural eDNA samplers, accumulating genetic traces from surrounding organisms. The cryogenic storage at the ESB preserves any eDNA in the samples in its original state. In this thesis, Chapter I serves as an introductory chapter, outlining the general chances and challenges of metabarcoding for assessing biodiversity. Chapter II focuses on primer design and testing the utility of ESB sampling species like mussels and macroalgae for characterizing the surrounding community. Both chapters form the basis for Chapters III to V, which report the use of ESB time series to uncover sample-associated communities and the changes they undergo. Chapter III illustrates the value of these time series by revealing the invasion trajectory of an alien barnacle into German coastal waters and linking the process to climate change. Chapter IV forms the core of this thesis by presenting an expanded measurement of biodiversity change in ESB time series across different taxonomic groups and ecosystem types. Here, a gradual compositional change (turnover) is reported from bacterial, fungal, microeukaryotic, and metazoan communities tending to either spatial homogenization or differentiation. Observed trends are tested for significance using a dynamic model of community ecology based on the equilibrium theory of island biogeography. The model reveals significantly accelerated turnover rates across all taxonomic groups and ecosystems investigated, suggesting a common, anthropogenically induced driver of biodiversity change. Since these analyses most likely include DNA derived from dead as well as from living organisms, Chapter V aims to separate both groups by metabarcoding both DNA and less stable ribosomal RNA from mussel samples. Contrary to the hypothesis, RNA is detectable from both living endobionts and dietary taxa. However, it outcompetes DNA in detecting microeukaryotic biodiversity. In summary, this thesis demonstrates the outstanding potential of archived ESB samples for retrospective biodiversity monitoring, a resource that offers many further untapped opportunities for future biodiversity research at multiple scales.

Biotic communities experienced significant changes in recent decades. Climate change, the overexploitation of natural resources and the immigration of invasive species are major drivers for this change and present unknown challenges for communities worldwide. To assess the impact of these drivers, standardised long-term studies are required, which are currently lacking for many species and ecosystems. Analysing environmental samples and the DNA of associated organisms using metabarcoding and high-throughput sequencing provides a cost-efficient and rapid way to generate the high-resolution biodiversity data which is so direly needed. In this thesis, I demonstrate the great potential of using samples from the German Environ- mental Specimen Bank (ESB), a long-term monitoring archive that has been collecting and cryogenically storing highly standardised environmental samples since 1985. Modern analytical methods enable retrospective long-term biodiversity monitoring using these samples. In the first chapter, I illustrate metabarcoding as a central method, discussing its strengths and drawbacks, how to avoid them, and new application approaches. This chapter provides the methodological basis for the following studies. In subsequent chapters, I present time series analyses of communities associated with these environmental samples. While for Chapter two the focus is on terrestrial arthropod communities, in Chapter three aquatic and terrestrial communities across the tree of life are analysed. A null model was developed for this survey for robust conclusions. The studies covered the last three decades and revealed substantial compositional changes across all ecosystems. These changes deviated significantly from the model, indicating that the changes are occurring faster than expected. Moreover, a trend toward homogenization in many terrestrial communities was uncovered. Climate change and the immigration of invasive species in combination with the loss of site-specific species are suspected to be the main drivers for this. In a follow-up study, changes of arthropod communities in German and South Korean terrestrial ecosystems were compared using ESB leaf samples from these two countries. Since both ESBs are harmonised in sample collection and processing, comparative analyses were applicable. This research covered the last decade and revealed substantial declines in species richness in Korea. Abiotic and biotic factors are discussed as potential drivers of these results. Finally, the possibility of assessing tree health by analysing changes in functional fungal groups using German ESB samples was investigated. The results indicate that increasing infestation of specific functional groups is a proxy for declining tree health, with further analyses planned. In this dissertation, I present the great potential of samples from long-term monitoring archives to conduct retrospective biodiversity trend analyses across the tree of life. As technologies evolve, these samples will help to understand past and predict future ecosystem changes.

Social virtual environments allow their users to meet and collaborate in a shared three-dimensional space, even when far apart from each other in the real world. Within these spaces, the appearance and interaction capabilities of both users and environments can be adapted and changed in a myriad of ways. To enable virtual environments to fulfill their potential of supporting a wide variety of collaboration use-cases, both the impacts of basic interaction design decisions and the individual needs of specific usage areas need to be explored further. This thesis approaches this topic in two ways. First, the basic building blocks of collaboration in social virtual environments are explored by asking the question: "How can social virtual spaces that allow interaction beyond real-world constraints utilize the potential of mutual assistance and shared workflows between multiple users?". Going into further detail for a serious use-case in which direct collaborative interactions and their effect on the included users are especially important, it then explores the potential of collaborative virtual spaces in the therapy domain by asking "How can the potential of social virtual spaces be utilized to support and improve therapy encounters?" With regards to the first research question, the thesis presents two theoretical frameworks detailing different aspects of supporting smooth and varied collaboration processes. In addition, several user studies on the topic of collaborative virtual interaction are described, focusing on the role that different users can play during shared interaction and the effects that this distribution of roles and responsibilities has on both the performance and experience of the involved user pairs. The results presented for this first research question show that social virtual spaces have the potential to provide dedicated support for collaborative workflows. To enable users to adapt their working mode individually and as a team, interaction techniques should complement a team's natural interaction and communication. When presenting novel interactions to users, providing them with a way to support each other can ease their adaptation to these interactions. In these cases, the inclusion of all interested collaborators as active participators should be prioritized in order to let all users benefit from being immersed in a virtual environment. Addressing the combination of social virtual spaces with therapy in relation to the second research question, this thesis presents the result of a series of interviews with practicing physio- and psychotherapists. Motivated by the recorded expert feedback, it also reports on two more detailed explorations of specific areas of interest. The work presented for the second research question demonstrated the promise of using virtual environments in both exercise- and conversation-based therapy practice. Investigating the potential of shared interactions, the exploration of virtual recordings and the adaptation of virtual appearances, the presented work uncovered several topic areas that could be further explored regarding their possible use in the treatment of patients. Taken together, the six research articles presented in this thesis show both the value of supporting and understanding shared interactions in virtual spaces and their potential place in serious use-cases like the therapy domain. When introducing shared virtual environments to new user groups, the opportunity for mutual support through shared interaction techniques could be a crucial building block towards making virtual spaces both accessible and attractive to a variety of users.

Entrepreneurship is recognized as an important discipline to achieve sustainable development and to address sustainability goals without losing sight of economic aspects. However, entrepreneurship rates are rather low in many industrialized countries with high income levels. Research clearly shows that there is a gap in the entrepreneurial process between intentions and subsequent actions. This means that not everyone with entrepreneurial ambitions also follows through and implements actions. This gap also exists for aspects of sustainability. As a result, there is a need to better understand the traditional and sustainability-focused entrepreneurial process in order to increase corresponding actions. This dissertation offers such a comprehensive perspective and sheds light on individual and contextual predictors for traditional and sustainability-focused behavior of entrepreneurs and self-employed across four studies. The first three studies focus on individual predictors. By providing a systematic literature review with 107 articles, Chapter 2 highlights the ambivalent role of religion for the entrepreneurial process. Relying on the theory of planned behavior (TPB) as theoretical basis, religion can have positive effects on entrepreneurial attitudes and behavioral control, but also negative consequences for other aspects of behavioral control and subjective norms due to religious restrictions. The quantitative empirical study in Chapter 3 similarly relies on the TPB and sheds light on individual perceptual factors influencing the sustainability-related intention-action gap in entrepreneurship. Using data from the 2021 Global Entrepreneurship Monitor (GEM) Adult Population Survey (APS) including 22,008 early-stage entrepreneurs from 44 countries worldwide, the results support our theoretical reasoning that sustainability-focused intentions are positively related to social entrepreneurial actions. In addition, it is demonstrated that positive perceptual moderators such as self-efficacy and knowing other entrepreneurs as role models strengthen this relationship while a negative perception such as fear of failure restricts social actions in early-stage entrepreneurship. The next quantitative empirical study in Chapter 4 examines the behavioral consequences of well-being at a sample of 6,955 German self-employed during COVID-19. This chapter builds on two complementary behavioral perspectives to predict how reductions in financial and non-financial well-being relate to investments in venture development. In this regard, reductions in financial well-being are positively related to time investments, supporting the performance feedback perspective in terms of higher search efforts under negative performance. In contrast, reductions in non-financial well-being are negatively related to time and monetary investments, yielding support for the broadening-and-build perspective indicating that negative psychological experiences narrow the thought-action repertoire and hinder resource deployment. The insights across these first three studies about individual predictors indicate that many different, subjective beliefs, perceptions and emotional states can influence the entrepreneurial process making entrepreneurship and self-employment highly individualized disciplines. The last quantitative empirical study provides an explorative view on a large number of contextual predictors for social and ecological considerations in entrepreneurial actions. Combining GEM data from 2021 on country level with further information from the World Bank and the OECD, a machine learning approach is employed on a sample of 84 countries worldwide. The results suggest that governmental and regulatory as well as cultural factors are relevant to predict social and ecological considerations. Moreover, market-related aspects are shown to be relevant predictors, especially socio-economic factors for social considerations and economic factors for ecological considerations. Overall, the four studies in this dissertation highlight the complexity of the entrepreneurial process being determined by many different individual and contextual factors. Due to the multitude of potential predictors, this dissertation can only give an initial overview of a selection of factors with many more aspects and interdependencies still to be examined by future research.

In this dissertation, I analyze how large players in financial markets exert influence on smaller players and how this affects the decisions of the large ones. I focus on how the large players process information in an uncertain environment, form expectations and communicate these to smaller players through their actions. I examine these relationships empirically in the foreign exchange market and in the context of a game-theoretic model of an investment project. In Chapter 2, I investigate the relationship between the foreign exchange trading activity of large US-based market participants and the volatility of the nominal spot exchange rate. Using a novel dataset, I utilize the weekly growth rate of aggregate foreign currency positions of major market participants to proxy trading activity in the foreign exchange market. By estimating the heterogeneous autoregressive model of realized volatility (HAR-RV), I find evidence of a positive relationship between trading activity and volatility, which is mainly driven by unexpected changes in trading activity and is asymmetric for some of the currencies considered. My results contribute to the understanding of the drivers of exchange rate volatility and the role of large players in the flow of information in financial markets. In Chapters 3 and 4, I consider a sequential global game of an investment project to examine how a large creditor influences the decisions of small creditors with her lending decision. I pay particular attention to the timing of the large player’s decision, i.e. whether she makes her decision to roll over a credit before or after the small players. I show that she faces a trade-off between signaling to and learning from small creditors. By being a focal point for coordination, her actions have a substantial impact on the probability of coordination failure and the failure of the investment project. I investigate the sensitivity of the equilibrium by comparing settings with perfect and imperfect learning. The results highlight the importance of signaling and provide a new perspective on the idea of catalytic finance and the influence of a lender-of-last-resort in self-fulfilling debt crises.

In den letzten Jahren hat die Nutzung von Drohnen deutlich zugenommen. Dies liegt unter anderem an der Leistungssteigerung, der guten Verfügbarkeit und an dem einfachen Einsatz von Drohnen. Damit sind auch Anwendungen in der Forschung möglich geworden, die zuvor unmöglich oder mit hohen Kosten verbunden waren. Als Sensor zur Datenaufzeichnung findet im Bereich der Forschung häufig eine Kamera Verwendung. Zusammen mit einer Drohne können Bereiche einfach und kostengünstig überflogen und dabei erkundet, beobachtet oder überwacht werden. Neben der Kamera als Sensor werden auch häufig Multispektralkameras und Lidar eingesetzt. Dagegen findet Radar im Bereich von kleinen Drohnen kaum Anwendung. Ziel dieser Forschungsarbeit war es zu untersuchen, ob neuste Radartechnik einen Mehrwert in der Fernerkundung mit kleinen Drohnen bieten kann. Hierfür wurden moderne Radarsensoren aus dem Automobilbereich ausgewählt. Als Drohnen wurden sowohl Quadrocopter als auch eine Starrflügler-Drohne eingesetzt. Für die Analyse, Berechnung und Auswertung der Daten wurde MATLAB verwendet. Der erste Ansatz beruhte auf einer Starrflügler-Drohne, die sich durch ihren freien Zugriff auf die Steuerung auszeichnet. Dadurch können auch spezielle Anforderungen an die Flugregelung berücksichtigt werden. Allerdings können mit einer Starrflügler-Drohne keine langsamen oder sogar statische Luftaufnahmen erstellt werden, um Erfahrung mit den Radardaten zu erlangen. Aus diesem Grund wurde anschließend ein Radar-Messsystem entworfen, das unabhängig von der Drohne eingesetzt werden kann. Zusammen mit einem Quadrocopter konnten so statische Radarmessungen durchgeführt werden, um die Verwendbarkeit der Radardaten in der Fernerkundung zu bestätigen. Das Messsystem konnte so aber nur für 2-dimensionale Anwendungen eingesetzt werden. In der weiteren Forschungsarbeit wurde untersucht, ob es möglich ist, mit einem Radarsensor der nur in 2-dimensionen misst eine 3-dimensionale Aufzeichnungen zu erstellen. Als Versuchsobjekt wurde eine Hütte gewählt, die Anhand der Radardaten dargestellt werden sollte. Dafür wurde ein Prozess zur Datenverarbeitung mit elf Schritten entworfen, womit die Hütte auf 0,6 Meter genau rekonstruiert werden konnte. Im letzten Teil der Forschungsarbeit wurde untersucht, ob sich die Genauigkeit des Messsystems erhöhen lässt, um noch mehr Anwendungsfälle bedienen zu können. Dafür wurde ein neuer Radarsensor eingesetzt, der eine höhere Genauigkeit besitzt. Die Forschungsarbeit konzentrierte sich darauf, die Abhängigkeit der Radardaten zum ungenauen Lagesensor aufzulösen. Dabei wurde die Fluglage über die Radardaten selbst berechnet, womit die Fluglage genauer bestimmt werden kann als allein über den Lagesensor. Erst damit kann die höhere Genauigkeit des neuen Radarsensors auch tatsächlich ausgenutzt werden. Mit den Ergebnissen der Forschungsarbeit sowie den vorgestellten Radarsensoren, stehen der Fernerkundung mit kleinen Drohnen, neben den klassischen Sensoren, zukünftig auch Radarsensoren zur Verfügung. Mit dem Messsystem und den Erkenntnissen aus der Forschungsarbeit werden bereits erste spezifische Anwendungen in Forschungsprojekten untersucht. Darüber hinaus konnten auch Anwendungsfälle außerhalb der Fernerkundung identifiziert werden. Die Weiterentwicklung im Bereich des autonomen Fahrens wird für Leistungssteigerungen bei Radarsensoren sorgen. Damit stehen auch der Fernerkundung zukünftig noch bessere Radarsensoren zur Verfügung.

Der ökologische Zustand der Erde befindet sich infolge von Umweltverschmutzung, Abfallaufkommen und CO₂-bedingtem Klimawandel in einem kritischen Zustand. Mit rund 40 % trägt der Bau- und Gebäudesektor erheblich zu den globalen Treibhausgasemissionen bei. Holz gilt als klimafreundliche Alternative zu Beton und Stahl, bedarf jedoch ebenfalls einer nachhaltigen Nutzung. Die Kreislaufwirtschaft bietet mit der Wiederverwendung ein zukunftsweisendes Konzept: So sind etwa 45% des beim Rückbau von Gebäuden anfallenden Holzes potenziell als Rohstoff nutzbar. Dadurch werden alternative Rohstoffquellen erschlossen und das Abfallaufkommen reduziert. Trotz dieses Potenzials liegt der Zirkularitätsgrad der Weltwirtschaft derzeit nur bei 7,2 %. Vor diesem Hintergrund untersucht die Dissertation, welche Wettbewerbsstrategien und welche organisationalen Fähigkeiten die Entwicklung zirkulärer Geschäftsmodelle fördern. Der Fokus liegt auf der Holzindustrie der DACH-Region, die historisch durch forstwirtschaftliche Nachhaltigkeit geprägt ist, jedoch bislang überwiegend linearen Strukturen folgt. Die Arbeit kombiniert theoretische Fundierung, eine vierjährige Literaturrecherche, Experteninterviews sowie im Zentrum eine quantitative Unternehmensbefragung (n = 200). Daraus wurde eine aktivitätsorientierte Skala zur Bewertung der Zirkularität eines Geschäftsmodells entwickelt. Analysiert wurden drei Perspektiven: Fähigkeiten, Strategien und Stakeholder. Im Kontext der Fähigkeitsperspektive wurde ermittelt, dass die dynamischen Fähigkeiten positive Implikationen auf die Umsetzung von Zirkularität haben. Im Forschungsfeld der Strategieperspektive wurde deutlich, dass die Innovationsführerschaft positive Effekte auf die Umsetzung der Kreislaufwirtschaft besitzt. Zudem weisen sowohl die Innovationsführerschaft als auch die Qualitätsführerschaft einen positiven indirekten Effekt über die dynamischen Fähigkeiten auf die Entwicklung zirkulärer Geschäftsmodelle auf. Im Rahmen der Stakeholderperspektive wurde eruiert, dass der Stakeholder-Druck im Zusammenwirken mit einem grünen Unternehmensimage eine Katalysator-Wirkung besitzt. Der Einfluss der Interessengruppen führt dazu, dass die Unternehmen ein grünes Image in eine substanzielle Umsetzungsphase überführen. Darüber hinaus wurde ersichtlich, dass der Stakeholder-Druck als zentraler Veränderungsfaktor wirkt. Während die direkten Auswirkungen der dynamischen Fähigkeiten durch den Druck zurückgehen, nehmen die indirekten Effekte auf die Erreichung von Zirkularität zu. Abschließend werden Handlungsempfehlungen für Unternehmen sowie wissenschaftliche Implikationen und zukünftige Forschungsmöglichkeiten abgeleitet.

When natural phenomena and data-based relations are driven by dynamics which are not purely local, they cannot be described satisfactorily by partial differential equations. As a consequence, mathematical models governed by nonlocal operators are of interest. This thesis is concerned with nonlocal operators of the form $\mathcal{L}u(x) = PV \int_{\mathbb{R}^d} (u(x)-u(y)) K(x,dy), x \in \mathbb{R}^d$, which are determined through a family of Borel measures $K=(K(x, \cdot))_{x \in \mathbb{R}^d}$ on $\mathbb{R}^d$ and which act on the vector space of Borel measurable functions $u: \mathbb{R}^d \rightarrow \mathbb{R}$. For a large class of families $K$, namely those where $K$ is a symmetric transition kernel satisfying a specific non-degeneracy condition, a variational theory for nonlocal equations of the type $\mathcal{L}u=f$ is established which builds upon gadgets from both measure theory and classical analysis. While measure theory is used to provide a nonlocal integration by parts formula that allows to set up a reasonable variational formulation of the above equation in dependency of the particular boundary condition (Dirichlet, Robin, Neumann) considered, Hilbert space theory and fixed-point approaches are utilized to develop sufficient conditions for the existence of variational solutions. This theory is then applied to two specific realizations of $\mathcal{L}$ of interest before a weak maximum principle is established which is finally used to study overlapping domain decomposition methods for the nonlocal and homogeneous Dirichlet problem.

Bilevel problems are optimization problems for which parts of the variables are constrained to be an optimal solution to another nested optimization problem. This structure renders bilevel problems particularly well-suited for modeling hierarchical decision-making processes. They are widely applicable in areas such as energy markets, transportation systems, security planning, and pricing. However, the hierarchical nature of these problems also makes them inherently challenging to solve, both in theory and in practice. In this thesis, we study different nonlinear problem settings for the nested optimization problem. First, we focus on nonlinear but convex bilevel problems with purely integer variables. We propose a solution algorithm that uses a branch-and-cut framework with tailored cutting planes. We prove correctness and finite termination of the method under suitable assumptions and put it into context of existing literature. Moreover, we provide an extensive numerical study to showcase the applicability of our method and we compare it to the state-of-the-art approach for a less general setting on suitable instances from the literature. Furthermore, we discuss challenges that arise when we try to generalize our approach to the mixed-integer setting. Next, we study mixed-integer bilevel problems for which the nested problem has a nonconvex and quadratic objective function, linear constraints, and continuous variables. We state and prove a complexity-theoretical hardness result for this problem class and develop a lower and upper bounding scheme to solve these problems. We prove correctness and finite termination of the proposed method under suitable assumptions and test its applicability in a numerical study. Finally, we consider bilevel problems with continuous variables, where the nested problem has a convex-quadratic objective function and linear constraints. We reformulate them as single-level optimization problems using necessary and sufficient optimality conditions for the nested problem. Then, we explore the family of so-called P-split reformulations for this single-level problem and test their applicability in a preliminary numerical study.

Die Arbeit untersucht den bundesdeutschen Diskurs zur europäischen Integration seit 1990 aus diskurslinguistischer Perspektive und versteht ihn als Aushandlungsraum europäischer Identitätskonstruktionen. Ausgangspunkt ist die Annahme, dass institutionelle Vertiefung und geografische Erweiterung der EU nicht allein als verrechtlichte Integrationsschritte zu begreifen sind, sondern stets auch identitätspolitische Dimensionen tragen. Ziel der Studie ist es, die sprachliche Konstituierung der EU als identitätspolitisches Referenzsystem sichtbar zu machen und damit eine diskurslinguistische Ergänzung zur interdisziplinären Integrationsforschung zu leisten. Auf Grundlage eines diachronen Korpus, das zentrale integrationspolitische Etappen und Krisenphasen umfasst, wird ein Mixed-Methods-Ansatz entwickelt, der korpusgeleitete Verfahren mit der hermeneutischen Annotation diskurslinguistischer Kategorien verbindet. Analysiert werden nicht nur lexikalisch-semantische Repräsentationen Europas, sondern vor allem diskursive Grundfiguren wie Einheit, Vielfalt, Eigenes und Fremdes sowie deren Verbindung zu politischen Sinnzuschreibungen. Die Ergebnisse zeigen, in welchem Maße sich im deutschen Diskurs ein stabiler identitätspolitischer Bezugspunkt zur EU herausgebildet hat, wie sich normative Leitbilder und funktionale Rationalitäten überlagern und wie europäische Integration sprachlich zwischen symbolischer Aufladung und strategischer Instrumentalisierung verhandelt wird.

Perennial crops eliminate soil disturbance and reduce the amount of synthetic chemicals that are applied to the soil, improving soil biodiversity and food web structure. Additionally, perennial cropping is characterised by all year-round surface coverage which benefits soil biota in terms of habitat and food sources. Perennial intermediate wheatgrass (Thinopyrum intermedium, IWG) was domesticated and commercialised by The Land Institute in Kansas as Kernza® and serves as an example for these nature-based solutions. It develops an extensive root system that has a higher nutrient retention, possibly reducing nutrient runoff. It thereby follows a more resource-conservative strategy with improved belowground-oriented resource allocation in its root system. This may reduce the need for excessive fertiliser as the crop has a higher nitrogen efficiency, among other things. IWG promoted the earthworm community and its diversity, more specifically, the occurrence of epigeic species (litter inhabitants), since those species benefit from the increased soil coverage and elimination of disturbances in the soil. As IWG creates a dense and extensive root system, as shown by the increased occurrence of root-feeding nematodes, endogeic species (horizontal burrowers) are supported through the provision of a reliable food source. IWG was characterised as a mostly undisturbed system with a highly structured food web through nematode analysis, as expressed through the promotion of structure indicators, for example, that are sensitive to disturbances in the soil and are therefore supported under no-till management. The root microbiome is continuously being shaped by the host as the crop regrows from the roots each vegetation period. This creates a symbiotic relationship and a beneficial feedback loop for the crop. Resultantly, the root-endophytic microbiome under IWG had a higher network complexity, connectivity and stability compared to annual wheat. The regrowth from the roots for IWG requires increased nutrient and energy storage, which was indicated by increased starch values. Correspondingly, the longer residence time of the roots in the soil resulted in higher lignin values. Furthermore, the decomposition pathway was dominated by fungivorous nematodes which may correspond to stimulated nutrient cycling and a heterogeneous resource environment, as seen for low input systems. Overall, perennial wheat cultivation improved soil biodiversity already after an establishment of 3-6 years. As those benefits were present for all three countries, the varying soil and climate conditions do not seem to interfere with the positive effect of perennial wheat on the soil ecosystem, demonstrating a wide transferability and adaptability of the crop onto other study sites as well. Enhanced complexity and connectivity of the food web in comparison to annual wheat may indicate a resistance against abiotic stress, suggesting IWG cultivation as a viable option for a sustainable and resilient agriculture. The improvement in nutrient cycling and the resource-efficient cultivation strategy for IWG could enable cultivation on marginal land where annual crop cultivation is not possible as the soils are susceptible to erosion and nutrient runoff. This opens up new possibilities for agricultural cultivation on previously unused land, thus contributing to food security in the future.

Price indices play a vital role in economic measurement as they reflect price levels and measure price fluctuations. Price level measures are used with macroeconomic indicators to express them in real terms. These measures are also used to index wages, rents, and pensions. Furthermore, they are used as a reference for monetary policy conducted by central banks. Therefore, the provision of accurate price indices is one of the most important goals of National Statistical Institutes (NSIs), and numerous studies have been devoted to this goal. This cumulative dissertation also contributes to this goal. It contains four chapters, each of which represents a separate research. The first two studies are devoted to the treatment of seasonal products by using different price index methods. The first research is co-authored with Ken van Loon. The third research is dedicated to finding the most accurate method to make price predictions for missing products. The fourth research is focused on the treatment of products by using different price index methods when products’ quality characteristics are available.

Income composition can have a significant impact on workers’ well-being, productivity, and career paths. Wages often include a variety of components, such as unconditional bonuses, profit-sharing payments, and incentives based on the individual performance of employees. Each of these may influence employee labour outcomes differently and the worker composition may matter for managers when designing the salary package. Simultaneously, workers’ employment choices and well-being are influenced by income outside the job, such as inheritances and lottery winnings, as well as by external factors like technological change. This dissertation includes five empirical studies that investigate these issues, yielding new insights on the role of monetary gifts, financial incentives, labour market institutions, and technology disruptions in affecting employees’ labour and well-being outcomes.

This dissertation examines how individuals unlock their personal power by investigating individual differences in self-regulation, in particular, how situational conditions interact with the personality dispositions of action versus state orientation. Action-oriented individuals are well able to regulate their affective states and to bridge the intention–behavior gap, showing initiative, implementing demanding intentions, and resisting temptations. State-oriented individuals, by contrast, often struggle to regulate affect and experience difficulties enacting intentions, especially under demanding conditions, tending to hesitate and ruminate. While extensive research has highlighted the advantages of action orientation across various domains such as education and health, this thesis challenges the prevailing one-sided perspective that presents action orientation as inherently superior and frames state orientation negatively. Drawing on Personality Systems Interactions theory, the dissertation adopts a dynamic view that understands these dispositions as context-sensitive rather than fixed. The central assumption is that action and state orientation each require different kinds of situational conditions to fully unlock their potential. Across six empirical studies (overall N = 1,067) using a multimethod approach that combines experimental and survey-based research in diverse populations and contextual settings, this dissertation examines (1) action and state orientation as distinct dispositions, (2) their dynamic interaction with situational factors, and (3) ways to support each in mobilizing personal power. Overall, the findings show that each disposition offers unique advantages - they simply require different situational conditions for their potential to unfold.

Transnational protest movements continue to expose the enduring legacies of colonial exploitation and institutionalised racism within and beyond European cities. They foreground the systemic conditions under which Black lives are rendered disproportionately vulnerable to premature death. In doing so, they expose the enduring entanglements of racial capitalism, state violence and spatial exclusion. Through their ongoing political agitation these movements highlight the need for spatio-temporally situated and relationally embedded engagements with Black urban lives. My thesis responds to that call by examining place-making practices of enclosure and refusal throughout Black London’s post-World War II development. Grounded in the ethnographic narrative of “being halfway while shooting”, I explore how Black lives are enclosed by institutional racism, how this enclosure is spatialised and how Black and differently racialised Londoners refuse these spatial enclosures through everyday and collective place-making practices. At the intersection of structural constraint and the desire to enact Black freedom in London, I specifically foreground the emergence of fugitive place-making practices. Conceptually, I bring (critical) urban geography scholarship, Black studies and Black (British)Geographies scholarship into conversation. I develop “being halfway while shooting” as a relational concept that foregrounds the production of racialised urban knowledges, the multiplicity of Black enclosures, and the plurality of place-based strategies committed to refusal. I do so by stressing the relevance of Black fugitive thinking to account for the ongoing refusals that mark the relationship between Blackness and the British city. Methodologically, I adopt a research-activist ethnographic approach, grounded in my long-term engagement with a housing campaign in East London that organises around the housing needs of London’s racialised and gendered urban poor. Using qualitative methods - archival research, interviews, (non-)participant observations, document and media analysis - I embed contemporary struggles into long and ongoing histories of racial-capitalist urban development as well as Black and multi-ethnic refusal. The empirical chapters trace place-making practices of enclosure and refusal across London’s post-World War II urban development. By examining the aftermath of urban revolts and changing urban welfare regimes, I explore how racialised urban governance has been historically materialised in and through the city. At the same time, I foreground how within this racialised construction of the British city, Black and differently racialised Londoners continue to hold open the possibility of refusal through places in which communal care and self-determination can be enacted. I then turn to the struggle over housing in East London, showing how contemporary processes of racialised dehumanisation and ongoing displacement are both historically rooted and actively contested. In the final empirical chapter I accentuate the relevance of these findings for German-speaking critical urban geography debates. The research shows that racial capitalist urbanism reproduces enclosures through practices of value extraction, spatial displacement, and the policing of Black subjectivities. In response, Black and differently racialised Londoners engage in fugitive place-making. Rooted in communal care, political organisation, collective education and cultural affirmation, these practices reassert Black presence and belonging. They offer an enduring mode of place-based refusal and the ongoing possibility to stay in the city differently. These findings not only demonstrate the academic significance of my research but also underscore the urgent need to support the place-making practices of Black and differently racialised urban communities, who continue to refuse the racialised enclosure of the British city from within. From these empirical insights, I propose the concept of a fugitive sense of place - a theoretical lens that accounts for the racialised reproduction of urban space and the transformative place-making practices of those who refuse its logics. Rather than offering prescriptive policy recommendations, I call for a reorientation of urban geographical enquiry by centring Black spatial practices, knowledges and imaginations. Through the lens of “being halfway while shooting”, I argue for a rethinking of human habitation and urban theory through the lived experiences of Black survival and refusal. Attending to a fugitive sense of place, I propose new avenues for human geography research to explore how fugitive place-making practices reshape the meanings, conditions, and possibilities of urban life.