All nations participate in international trade, and for most economies, a substantial share of domestic output is exported, and a large part of total expenditure is on imported items. International trade is a central concern of all governments' economic policies. This book provides an introduction to the economic analysis of international trade policies, focusing on the effects of various policies and using this positive analysis both to determine which trade policies should be adopted and to explain why existing policies have been adopted. Aimed at students with a fairly rudimentary background in economic principles, and concentrating exclusively on trade issues, the book will be adopted on numerous courses in international economics. It features the most up-to-date material in the field, including imperfect competition, intra-industry trade, and the political economy of tariff barriers; and draws on examples from a range of countries at all levels of development.