Given the rapid emergence of regional economic arrangements in Asia, especially in Southeast Asia, it is useful to understand clearly what regionalism implies for the region, as well as to take stock as to the far-reaching and complicated effects of formal economic cooperation and integration. This book allows the reader to better understand the relevant international policies of the Southeast Asian economies, and to appreciate the potential lessons for other developing regions. It also focuses on the regionalism trend with an explicit application to ASEAN, as well as the implications of regionalism in the developed countries. The goal of this book is to survey the economics and political economy of regionalism in the Asian context from a variety of perspectives and using various techniques, from standard economic analysis of preferential trading arrangements to the political economy analysis of institutions in the historical and comparative contexts. It contains six case studies that support the analyses and facilitate a pedagogical approach to the associated issues.