Pascal Langer, Matthias Neuenkirch, Jerg Gutmann

• International sanctions have become an increasingly prominent instrument of foreign policy, yet their political, institutional, and societal consequences remain complex and often extend beyond their stated objectives. This dissertation contributes to the literature on international sanctions by examining their effects across five distinct but interconnected dimensions. The five studies investigate how sanctions affect emigration, coups d’état, interactions between political leaders, public-sector corruption, and governments’ compliance with their national constitutions. The dissertation yields several key findings. First, Western multilateral and United Nations sanctions increase emigration from targeted countries, particularly where freedom of expression is restricted, suggesting that exit can serve as an alternative response when opportunities for political voice are limited. Second, Western sanctions increase the probability of coups d’état, especially successful coups in non-democratic regimes and during the post-Cold War period. Third, greater similarity between political leaders substantially reduces the likelihood of sanction imposition, particularly for unilateral sanctions, demonstrating that interpersonal characteristics shape the use of economic coercion. Fourth, Western and UN sanctions are associated with temporary reductions in public-sector corruption in democratic target countries, with particularly pronounced effects when sanctions pursue democratization or human rights objectives. Finally, sanctions have opposing effects on constitutional compliance across political regimes. While sanctioned democracies tend to improve their adherence to constitutional rules, sanctioned autocracies become less compliant. Taken together, the findings demonstrate that the consequences of international sanctions depend critically on the political and institutional characteristics of targeted states, the actors imposing sanctions, and the design and objectives of sanction regimes. Sanctions can induce behavioral and institutional change, but they can also generate unintended consequences, including emigration and political destabilization. By integrating insights from international economics, political economy, and international relations, this dissertation advances a more differentiated understanding of sanctions as a foreign-policy instrument and highlights the importance of accounting for heterogeneous responses when assessing their effectiveness and broader consequences.