Research in international trade has changed dramatically over the last twenty years, as attention has shifted from countries and industries towards the firms actually engaged in international trade. The now-standard heterogeneous firm model posits measure zero firms that compete under...

We reconcile international trade theory with findings of enormous plant-level heterogeneity in exporting and productivity. Our model extends basic Ricardian theory to accommodate many countries, geographic barriers, and imperfect competition. Fitting the model to bilateral trade among the United...

This paper examines how country, industry and firm characteristics interact in general equilibrium to determine nations' responses to trade liberalization. When firms possess heterogeneous productivity, countries differ in relative factor abundance and industries vary in factor intensity,...

This paper presents a model of international trade that features heterogeneous firms, relative endowment differences across countries, and consumer taste for variety. The paper demonstrates that firm reactions to trade liberalization generate endogenous Ricardian productivity responses at the...