International institutions vary significantly in their performance, or the extent to which they solve societal problems. The Ozone regime is a textbook example of an international institution that reached its core goals, whereas the contribution of the UN Security Council to the peaceful settlement of international conflicts, or the World Bank for eradication of poverty, is doubted by many. But how can we assess and measure the success and failure of international organizations and other institutions in global governance more systematically, and how can we explain why some perform better than others? This seminar provides an introduction into IR scholarship on the effectiveness of international institutions. First, participants learn to distinguish important concepts that describe the output-side of global governance, such as performance, effectiveness, compliance,and organizational failure. Second, participants get to read empirical literature showing how performance and effectiveness are studied within and across different issue areas and types of institutions, with quantitative as well as qualitative methods. Third, participants study and assess case studies of institutional performance issued by the “Multilateral Organization Performance Assessment Network” (MOPAN).