Comparative Advantage and the Welfare Impact of European Integration, joint with Jing Zhang Abstract: This paper investigates the welfare gains from European trade integration, and the role of comparative advantage in determining the magnitude of those gains. We use a multi-sector Ricardian model implemented on 79 countries, and compare welfare in the 2000s to a counterfactual scenario in which Eastern European countries are closed to trade. For Western European countries, the mean welfare gain from trade integration with Eastern Europe is 0.16%, ranging from zero for Portugal to 0.4% for Austria. For East European countries, gains from trade are 9.23% at the mean, ranging from 2.85% for Russia to 20% for Estonia. For Eastern Europe, comparative advantage is a key determinant of the variation in the welfare gains: countries whose comparative advantage is most similar to Western Europe tend to gain less, while countries with technology most different from Western Europe gain the most. JEL Classification Codes: F11, F14, F15 Keywords: European integration, Ricardian models of trade, welfare, comparative advantage