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...

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...