In this paper, I examine the relationship between increasing returns to scale and the geographic concentration of economic activity. Using data on U.S. counties, I estimate the structural parameters of the Krugman (1991) model of economic geography. The specification I use, which is derived from...

This paper highlights the importance of natural resource concentration and ethnic group regional concentration for ethnic conflict. A new type of bargaining failure due to multiple types of potential conflicts (and hence multiple threat points) is identified. The theory predicts war to be more...

Whether the danger invoked is nuclear war or genetically modified foods, far more people in some countries than in others say they are afraid. Using data from six surveys, I show that the levels of reported fear of different dangers correlate strongly across both individuals and countries. I...

We use new theory and data to study how firms endogenously form production networks across regions and countries. Supplier and buyer relationships form depending on firms' productivity and geographic location. We characterize the normative and positive properties of the spatial distribution of...

We examine how exposure of Chinese firms to the Covid-19 shock varied with a cluster index (measuring spatial agglomeration of firms in related industries) at the county level. Two data sources are used: entry flows of newly registered firms in the entire country, and an entrepreneur survey...

We document geographic concentration by both venture capital firms and venture capital-financed companies in three cities - San Francisco, Boston, and New York. We find that firms open new satellite offices based on the success rate of venture capital-backed investments in an area. Geography is...

This paper evaluates the role of regional cluster composition in the economic performance of industries, clusters and regions. On the one hand, diminishing returns to specialization in a location can result in a convergence effect: the growth rate of an industry within a region may be declining...

We explore the impact of rising incomes at the top of the distribution on spatial sorting patterns within large U.S. cities. We develop and quantify a spatial model of a city with heterogeneous agents and non-homothetic preferences for neighborhoods with endogenous amenity quality. As the rich...

W. Arthur Lewis argued that a new international economic order emerged between 1870 and 1913, and that global terms of trade forces produced rising primary product specialization and de-industrialization in the poor periphery. More recently, modern economists argue that volatility reduces growth...

We study the distribution of economic activity, as proxied by lights at night, across 250,000 grid cells of average area 560 square kilometers. We first document that nearly half of the variation can be explained by a parsimonious set of physical geography attributes. A full set of country...