Title: International trade and labor markets
Description: International trade is typically believed to lead to aggregate welfare gains for trading countries. However, it is also often viewed as a source of growing social disparity--by causing unemployment and greater inequality within countries--which calls for an offsetting policy response. This dissertation consists of three theoretical essays studying these issues. The first chapter develops a model of international trade with labor market frictions that differ across countries. We show that differences in labor market institutions constitute a source of comparative advantage and lead to trade between otherwise similar countries. Although trade ensures aggregate welfare gains for both countries, the more flexible country stands to gain proportionately more. An increase in the country's labor market flexibility leads to welfare gains at home, but causes welfare losses in the trading partner via decreased competitiveness of foreign firms. Trade can increase or decrease unemployment by inducing an intersectoral labor reallocation generating rich patterns of unemployment.

The second chapter proposes a new framework for thinking about the distributional consequences of trade that incorporates firm and worker heterogeneity, search and matching frictions in the labor market, and screening of workers by firms. Larger firms pay higher wages and exporters pay higher wages than non-exporters. The opening of trade enhances wage inequality and raises unemployment, but expected welfare gains are ensured if workers are risk neutral. And while wage inequality is larger in a trade equilibrium than in autarky, reductions of trade impediments can either raise or reduce wage inequality. Conventional wisdom suggests that the optimal policy response to rising income inequality is greater redistribution. The final chapter studies an economy in which trade is associated with a costly entry into the foreign market, so that only the most productive agents can profitably export. In this model, trade integration simultaneously leads to rising income inequality and greater efficiency losses from taxation, both driven by the extensive margin of trade. As a result, the optimal policy response may be to reduce the marginal taxes, thereby further increasing inequality. In order to reap most of the welfare gains from trade, countries may need to accept increasing income inequality.