This volume is a collection of papers that apply general equilibrium theory in order to obtain policy relevant insights on topical issues of international trade and migration. The first set of papers focuses on European integration, applying dynamic numerical general equilibrium methods to quantify the effects of geographic extension of the European Union, including the effects of Eastern enlargement of the EU on incumbent Western member countries. The second set of papers deals with the trade effects of WTO membership, with special focus on the so-called extensive country margin, where new international trading relationships are formed. The third set of papers focuses on immigration, offering a rigorous theoretical analysis of the so-called immigration surplus as well as an econometric estimation of the gains and pain that Germany has forgone by initially restricting immigration from new EU member countries after the EU''s Eastern enlargement in 2004. And finally, the book contains a set of theoretical papers on the distributional effects of offshoring. Contents: Introduction; Modeling EU-Type Economic Integration: Eastern Enlargement of the EU: Eastern Enlargement of the EU: Jobs, Investment and Welfare in Present Member Countries (Ben J Heijdra, Christian Keuschnigg and Wilhelm Kohler); Eastern Enlargement of the EU: A Comprehensive Welfare Assessment (Wilhelm Kohler); The Role of Distance and WTO Membership for Trade: Exploring the Intensive and Extensive Margins of World Trade (Gabriel J Felbermayr and Wilhelm Kohler); WTO Membership and the Extensive Margin of World Trade: New Evidence (Gabriel J Felbermayr and Wilhelm Kohler); Offshoring: A New Form of Trade, Conventional Mechanisms?: The Distributional Effects of International Fragmentation (Wilhelm Kohler); Aspects of International Fragmentation (Wilhelm Kohler); International Outsourcing and Factor Prices with Multistage Production (Wilhelm Kohler); The Bazaar Effect, Unbundling of Comparative Advantage, and Migration (Wilhelm Kohler); International Migration: Gains and Pains?: Immigration and Native Welfare (Gabriel J Felbermayr and Wilhelm Kohler); Can International Migration Ever Be Made a Pareto Improvement? (Gabriel Felbermayr and Wilhelm Kohler); Restrictive Immigration Policy in Germany: Pains and Gains Foregone? (Gabriel Felbermayr, Wido Geis and Wilhelm Kohler). Readership: Postgraduate students and researchers in the field of international economics.