This book advocates adding more open and radical regionalism to strategies for the financing of economic and social development in Africa, Asia, and Latin America. Editors Nancy Birdsall and Liliana Rojas-Suarez argue that agreements among countries within regions, rather than detracting from an open multilateral system, can promote greater integration into the global trading and financial system by helping to build the domestic institutions that developing countries need to cope with the challenges of the global economy. The essays in this volume point to the unrealized potential of regionalism in promoting not only reduction of trade barriers, but shared investment in infrastructure and enhanced policy cooperation in development of financial markets. The book also offers fresh insights on how regional development banks can catalyze collective action.