In the late 1980s regional integration emerged as one of the most important developments in world politics. It is not a new phenomenon, however, and this 1999 book presents an analysis of integration across time, and across regions. Walter Mattli examines projects in nineteenth- and twentieth-century Europe, but also in Latin America, North America and Asia since the 1950s. Using the tools of political economy, he considers why some integration schemes have succeeded while many others have failed; what forces drive the process of integration; and under what circumstances outside countries seek to join. Unlike traditional political science approaches, the book stresses the importance of market forces in determining the outcome of integration; but unlike purely economic analyses, it also highlights the impact of institutional factors. The book will provide students of political science, economics, and European studies with a framework for the study of international cooperation.