This paper examines the frequency, pervasiveness and determinants of product switching among U.S. manufacturing firms. We find that two-thirds of firms alter their mix of five-digit SIC products every five years, that one-third of the increase in real U.S. manufacturing shipments between 1972...

Standard models of international trade devote little attention to firms. Yet of the 5.5 million firms operating in the United States in 2000, just 4 percent engaged in exporting, and the top 10 percent of these exporting firms accounted for 96 percent of U.S. exports. Since the mid 1990s, a...

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...

Despite the fact that importing and exporting are extremely rare firm activities, economists generally devote little attention to the role of firms when discussing international trade. This paper summarizes key differences between trading and non-trading firms, demonstrates how these differences...

One of the most successful empirical relationships in international trade is the gravity equation, which relates bilateral trade flows between an origin and destination to bilateral trade frictions, origin characteristics, and destination characteristics. A key decision for researchers in...

Using newly-constructed spatially-disaggregated data for London from 1801-1921, we show that the invention of the steam railway led to the first large-scale separation of workplace and residence. We show that a class of quantitative urban models is remarkably successful in explaining this...

We develop a new framework for aggregating from micro to macro patterns of trade. We derive price indexes that determine comparative advantage across countries and sectors and the aggregate cost of living. If firms and products are imperfect substitutes, we show that these price indexes depend...

The observed uneven distribution of economic activity across space is influenced by variation in exogenous geographical characteristics and endogenous interactions between agents in goods and factor markets. Until the past decade, the theoretical literature on economic geography had focused on...

This paper explores the impacts of the Trump administration's trade policy on prices and welfare. Over the course of 2018, the U.S. experienced substantial increases in the prices of intermediates and final goods, dramatic changes to its supply-chain network, reductions in availability of...

We develop a model of human interaction to analyze the relationship between globalization and pandemics. Our framework provides joint microfoundations for the gravity equation for international trade and the Susceptible-Infected-Recovered (SIR) model of disease dynamics. We show that there are...