Centering on questions of the potential optimality of some trade protection, these original contributions present research at the frontier of international trade and trade policy. They expand and test the new trade theory that has developed during the last decade, incorporating elements of industrial organization and political economy into the study of trade structure and the formation of trade policy. Essays in the first two parts take up trade policy, addressing issues such as the formation of trading blocks, strategic trade policy, the political economy of protection, growth-oriented trade policies, and including empirical studies of the welfare effects of quality - upgrading voluntary export restrictions and import quotas. Essays in the third part discuss various structural issues such as trade in services, intersectoral adjustments, and the advantage of early entry. Elhanan Helpman and Assaf Razin are Professors of Economics at Tel Aviv University and NBER Research Associates. Contents: Trade Policy: Theory. Is Bilateralism Bad? Paul R. Krugman. Strategic Trade Policy and Direct Foreign Investment: When Are Tariffs and Quotas Equivalent? James A. Levinsohn. Making Altruism Pay in Auction Quotas, Kala Krishna. On the Ineffectiveness of Made-to-Measure Protectionist Programs, Aaron Tornell. Export Subsidies and Price Competition, Peter Neary. Adverse Selection in Credit Markets and Infant Industry Protection, Harry Flam and Robert W. Staiger. Protection, Politics, and Market Structure, Arye L. Hillman. Growth and Welfare in a Small Open Economy, Gene M. Grossman and Elhanan Helpman. Trade Policy: Evidence. Quality Upgrading and Its Welfare Cost in U.S. Imports, 1969-74, Randi Boorstein and Robert C. Feenstra. Counting the Cost of Voluntary Export Restraints in the European Car Market, Alasdair Smith and Anthony J. Venables. Structural Issues. Services in International Trade, Wilfred J. Ethier and Henrik Horn. First-Mover Advantages, Blockaded Entry, and the Economics of Uneven Development, James R. Markusen. Wage Sensitivity Rankings and Temporal Convergence, Ronald W. Jones and Peter Neary.