For the past twenty years, the theoretical literature on international cooperation has focused on overarching questions about whether cooperation is possible and how important it is. Now, this literature must address more focused questions about how the institutions of cooperation work and how they change state behavior. Moreover, after over fifty years of intense realist-antirealist debate in international relations (much of which turns on the question of the value and function of international agreements), no one has systematically collected data on important dimensions of international agreements. Hence, it is also time to collect such data to use them to confront both old and new theories. The first aspect of my research program develops a theoretical framework that explains international agreement design in terms of a set of logically derived and empirically testable hypotheses. The framework is based on a rational choice perspective in which actors purposefully design agreement and institutions to advance their joint interests. The theoretical aspect continues the line of work already established by Koremenos and others. The second aspect consists of collecting data on the characteristics of a large sample of international agreements drawn from the United Nations Treaty Series. The principal investigator focuses on four types of provisions: flexibility provisions, such as planned renegotiations and escape clauses, monitoring and compliance provisions, agreement scope (the number of issues covered), and references to other international agreements. These dimensions are motivated by important (and interesting) theoretical questions in the existing literature. The datasheet allows reseachers who study international cooperation to test their theories in much the same way as the Correlates of War and Militarized International Disputes datasets enable researchers who study international conflict to test their ideas. The data are available to the research community once assembled. As such, the project represents an important contribution to the research infrastructure of international relations. The feasibility of the proposed project is demonstrated by a successful test sample already drawn by the principal investigator. This sample reveals systematic variation in agreement provisions across issue areas. The third aspect consists of statistical analyses of the collected data. Given that this is the first data collection effort of its kind, this basic descriptive work represents an important contribution to the literature. Furthermore, and in contrast to the existing literature, which mainly illustrates theories of how states cooperate with case studies., these data allow researchers to test theories. The proposal also contains a substantial undergraduate and graduate teaching component. Several graduate students will use the datset in their dissertations. Undergraduate and graduate courses are to be developed based on the research design, with a particular focus on how to collect data that can be used to test empirically predictions from formal theory. These courses cover all aspects of the problem, with a special focus on the challenge of operationalizing theoretical variables.