Mechanisms of Cooperation in Social Dilemmas

This cumulative dissertation explores mechanisms that are used to promote cooperation in social dilemmas in the absence of a central enforcement authority capable of using coercion. It comprises five stand-alone but thematically connected research papers, each examining a different cooperation-enhancing mechanism. The dissertation is divided into two main parts. Part I focuses on mechanisms within the context of international climate policy, particularly the Paris Agreement. It investigates how pledging, naming and shaming, and trade linkage affect cooperation by drawing on a comprehensive expert survey. These mechanisms are evaluated based on their perceived effectiveness in promoting compliance of signatory states and enhancing collective action. Part II turns to more fundamental behavioral mechanisms of cooperation—direct and indirect reciprocity—using controlled laboratory experiments. The five research papers are framed by a general introduction and a concluding chapter. The introduction situates the research within the broader literature and explains the methodological approaches employed. The conclusion synthesizes the findings across both parts and highlights their implications for the design of international institutions. The five papers included in this dissertation can be summarized in the following way: Chapter 2 investigates the pledging mechanism under the Paris Agreement through an expert survey of climate policy elites. It finds that more ambitious pledges are viewed as more credible, with political factors like institutional quality playing a major role in credibility assessments, while economic indicators are less influential. European countries stand out for their ambitious and credible pledges. Chapter 3 examines naming and shaming as a compliance mechanism under the Paris Agreement. Support and perceived effectiveness strongly depend on national institutional quality and democratic governance. Furthermore, countries with higher public concern about climate change and credible pledges see the mechanism as more effective for themselves. Less capable countries see naming and shaming as less effective, pointing to the need for complementary strategies like capacity building. In terms of implementation, formal international bodies are preferred actors for enforcement compared to NGOs or the media. Chapter 4 explores attitudes toward linking climate policy with trade measures. Respondents from OECD countries generally view linkage of trade and climate policy as more legitimate, while non-OECD countries show more wariness. The chapter underscores the fragility of climate diplomacy due to diverging agendas and challenges in integrating trade enforcement without harming cooperation. Chapter 5 studies the impact of deliberate misreporting in the infinitely repeated prisoner’s dilemma. Allowing players to cheat by misreporting significantly lowers cooperation rates, especially when cheating attempts go undetected. The findings highlight the critical role of transparency and detection in maintaining cooperation in settings where monitoring can be manipulated. Chapter 6 investigates normative evaluations in indirect reciprocity. A relatively simple norm—only taking past actions into account—is strongly favored personally and socially, while more complex norms receive less support. However, this changes when subjects must recommend a norm to the entire group. Providing information on group norms, however, has only very limited effects on cooperation and norm adherence.