When economic activity is concentrated over space or over time, it is more efficient. Most production occurs in geographic hot spots, and most production occurs between 9 and 12 in the morning and 1 to 5 in the afternoon on weekdays. The thick-market efficiencies that encourage the concentration...

A Melitz-style model of monopolistic competition with heterogeneous firms is integrated into a simple New Economic Geography model to show that the standard assumption of identical firms is neither necessary nor innocuous. We show that re-locating to the big region is most attractive for the...

The distribution of firms in space is far from uniform. Some locations host the most productive large firms, while others barely attract any. In this paper, I study the sorting of heterogeneous firms across locations and analyze policies designed to attract firms to particular regions...

We identify negative spillovers exerted by large, successful manufacturing plants on other local production facilities in China. A short-lived alliance between the U.S.S.R. and China led to the construction of 150 "Million-Rouble plants" in the 1950s. Our identification strategy exploits the...

This review discusses frontier topics in economic geography as they relate to firms and agglomeration economies. We focus on areas where empirical research is scarce but possible. We first outline a conceptual framework for city formation that allows us to contemplate what empiricists might...

The degree of geographic concentration of individual manufacturing industries in the U.S. has declined only slightly in the last twenty years. At the same time, new plant births, plant expansions, contractions and closures have shifted large quantities of employment across plants, firms, and...

We consider the distribution of economic activity within a country in light of three leading theories - increasing returns, random growth, and locational fundamentals. To do so, we examine the distribution of regional population in Japan from the Stone Age to the modern era. We also consider the...

In many cities, restaurants and retail establishments are spatially concentrated. Economists have long recognized the presence of demand externalities that arise from spatial agglomeration as a possible explanation, but empirically identifying this type of spillovers has proven difficult. We...

We document a novel stylized fact: Using data for several countries, we show that export activity is disproportionately concentrated in larger cities - even more so than overall economic activity. We account for this fact by marrying elements of international trade and economic geography. We...