This collection of essays offers an assessment of the economic impact of preferential trade areas (PTAs) on member countries and the world. The text presents a theoretical analysis of the issues using economic models and also studies the relationahip between regionalism and multilateralism. Subsequent sections examine the role of PTAs in Asia, North America, and Latin America. The general theme of the volume is that, on balance, trade liberalization through PTAs is a mistake, and that the consequences of PTAs - increased tariffs for non-member countries - are likely to undermine the multilateral trading system.