This course focuses on economic interactions between countries. Topics may include classical theories for trade (comparative advantage, specific factors, resource abundance), modern theories of trade with heterogeneous firms and product differentiation, the gravity model and trade measurement, endogenous markups, international migration, and estimation of quantitative trade models. Prerequisites: Registration in the Business PhD Program, Department of Economics PhD Program, or permission of instructor. Approval of the Associate Dean for the Business PhD Program also required for non-PhD students