Since the mid-1990s, researchers have used micro datasets to study countries' production and trade at the firm level and have found that exporting firms differ substantially from firms that solely serve the domestic market. Across a wide range of countries and industries, exporting firms have...

Recent research in international trade emphasizes the importance of firms' extensive margins for understanding overall patterns of trade as well as how firms respond to specific events such as trade liberalization. In this paper, we use detailed US trade statistics to provide a broad overview of...

This paper examines the determinants of intra-firm trade in US imports using detailed country-product data. We create a new measure of product contractibility based on the degree of intermediation in international trade for the product. We find important roles for the interaction of country and...

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 develops a model of endogenous product selection by firms. The theory is motivated by new evidence we present on the importance of product switching by U.S. manufacturers. Two-thirds of continuing firms change their product mix every five years, and product switches involve more than...

This article develops a general equilibrium model of multiple-product, multiple-destination firms, which allows for heterogeneity in ability across firms and in product attributes within firms. Firms make endogenous entry and exit decisions and each surviving firm chooses optimally the range of...

This paper reviews the empirical evidence on firm heterogeneity in international trade. A first wave of empirical findings from micro data on plants and firms proposed challenges for existing models of international trade and inspired the development of new theories emphasizing firm...

This paper reviews the empirical evidence on firm heterogeneity in international trade. A first wave of empirical findings from micro data on plants and firms proposed challenges for existing models of inter- national trade and inspired the development of new theories emphasizing firm...

This paper examines the frequency, pervasiveness, and determinants of product switching by US manufacturing firms. We find that one-half of firms alter their mix of five-digit SIC products every five years, that product switching is correlated with both firm- and firm-product attributes, and...