The County Business Patterns data published by the US Census Bureau track employment by county and industry from 1946 to the present. Two features of the data limit their usefulness to researchers: (1) employment for the majority of county-industry cells is suppressed to protect confidentiality,...

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...

Do New York and Nashville face the same pressures from increased trade? This paper considers the role of international trade in shaping the product mix and relative wages for regions within the US. Using the predictions from a Heckscher-Ohlin trade model, we ask whether all the regions in the US...

This paper: outlines an algorithm for concording U.S. ten-digit Harmonized System export and import codes over time; describes the concordances we construct for 1989 to 2004; and provides Stata code that can be used to construct similar concordances for arbitrary beginning and ending years from 1989...

Many previous tests of Heckscher-Ohlin trade theory have found underwhelming support for the idea that countries' endowments determine their production and trade. This paper demonstrates that those efforts suffer from their focus on the narrower of the model's two potential equilibria, which...

This paper examines the relative "sophistication" of China's exports to the United States along two dimensions. First, I compare China's export bundle to those of the relatively skill- and capital-abundant members of the OECD as well as to similarly endowed U.S. trading partners. Second, I...

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 paper develops a general test of factor price equalization that is robust to unobserved regional productivity differences, unobserved region-industry factor quality differences and variation in production technology across industries. We test relative factor price equalization across...

Unit values of US imports at the product level reveal a substantial degree of vertical product differentiation among countries exporting to the US. This specialization is not apparent by looking solely at trade flows. Two trends stand out. First, the portion of US import products originating in...

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...