This paper introduces a new technique for testing the Heckscher-Ohlin model that allows for the possibility that countries with sufficiently disparate endowments specialize in unique subsets of goods. Results based upon industry-level data reject one-size-fits-all homogeneity in favor of Heckscher-Ohlin specialization. Results also reveal that industry-level data hide substantial intra-industry heterogeneity, violating the assumptions of the model and complicating the interpretation of results from earlier research. A methodology for adjusting industry output to reflect underlying product variation is introduced. Reestimation of the model using adjusted aggregates in place of standard industry classifications provides strong support for Heckscher-Ohlin specialization.

We develop a method for decomposing countries' observed export prices into quality versus quality-adjusted components using information contained in trade balances. Holding observed export prices constant, countries with trade surpluses are inferred to offer higher quality than countries running trade deficits. We account for variation in trade balances induced by horizontal and vertical differentiation, and we estimate the evolution of manufacturing quality for top exporters from 1989 to 2003. We find that observed unit value ratios can be a poor approximation for relative quality differences, countries' quality is converging more rapidly than their income, and countries appear to vary in terms of displaying “high-quality” versus “low-price” growth strategies.

This paper links the sharp drop in US manufacturing employment after 2000 to a change in US trade policy that eliminated potential tariff increases on Chinese imports. Industries more exposed to the change experience greater employment loss, increased imports from China, and higher entry by US importers and foreign-owned Chinese exporters. At the plant level, shifts toward less labor-intensive production and exposure to the policy via input-output linkages also contribute to the decline in employment. Results are robust to other potential explanations of employment loss, and there is no similar reaction in the European Union, where policy did not change.

If trade barriers are managed by inefficient institutions, trade liberalization can lead to greater-than-expected gains. We examine Chinese textile and clothing exports before and after the elimination of externally imposed export quotas. Both the surge in export volume and the decline in export prices following quota removal are driven by net entry. This outcome is inconsistent with a model in which quotas are allocated based on firm productivity, implying misallocation of resources. Removing this misallocation accounts for a substantial share of the overall gain in productivity associated with quota removal.

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 industry level that magnify countries' comparative advantage. Focusing on the wide range of firmlevel reactions to falling trade costs, the model also shows that, as trade costs fall, firms in comparative advantage industries are more likely to export, that relative firm size and the relative number of firms increases more in comparative advantage industries and that job turnover is higher in comparative advantage industries than in comparative disadvantage industries.

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 monopolistic competition and decide whether to export to foreign markets. However, much of international trade is dominated by a few “global firms,” which participate in the international economy along multiple margins and account for substantial shares of aggregate trade. We develop a new theoretical framework that allows firms to have large market shares and decide simultaneously on the set of production locations, export markets, input sources, products to export, and inputs to import. Using US firm and trade transactions data, we provide strong evidence in support of this framework's main predictions of interdependencies and complementarities between these margins of firm international participation. Global firms participate more intensively along each margin, magnifying the impact of underlying differences in firm characteristics and increasing their shares of aggregate trade.

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 that product adding and dropping induce large changes in firm scope. The behavior we observe is consistent with a natural generalization of existing theories of industry dynamics that incorporates endogenous product selection within firms. Our findings suggest that product switching contributes to a reallocation of resources within firms toward their most efficient use.

Intrafirm Trade and Product Contractibility by Andrew B. Bernard, J. Bradford Jensen, Stephen J. Redding and Peter K. Schott. Published in volume 100, issue 2, pages 444-48 of American Economic Review, May 2010

Wholesalers and Retailers in US Trade by Andrew B. Bernard, J. Bradford Jensen, Stephen J. Redding and Peter K. Schott. Published in volume 100, issue 2, pages 408-13 of American Economic Review, May 2010

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 U.S. trade statistics to provide a broad overview of how the margins of trade contribute to variation in U.S. imports and exports across trading partners, types of trade (i.e. arm’s-length versus related-party) and both short and long time horizons. Among other results, we highlight the differential behaviour of related-party and arm’s-length trade in response to the 1997 Asian financial crisis.