This paper develops and estimates a model of indivisibilities in shipping and economies of scale in consolidation. It uses highly detailed data on imports for which it is possible to observe the contents of individual containers. In the model, a firm is able to adapt to indivisibility...

This paper studies the sources of agglomeration economies in cities. We begin by introducing a simple dynamic spatial equilibrium model that incorporates spillovers within and across industries, as well as city-size effects. The model generates a dynamic panel-data estimation equation. 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...

This paper develops a two-region, two-sector general equilibriun model of location. The location of agricultural production is fixed, but ionopolistcally competitive manufacturing finns choose their location to maximize profits. If transportation costs are high, returns to scale weak, and the...

In recent empirical literature on spatial agglomeration, many papers find evidence consistent with location-specific externalities of some sort. Our willingness to accept evidence of agglomeration economies depends on how well key estimation problems have been addressed. Three issues are...

We complete the study of comparative statics initiated in Caplin and Leahy [2010], which introduced a new mathematical apparatus for understanding NTU allocation markets, as such covering the housing market and other markets for large indivisible goods. We introduce homotopy methods to...