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...

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 propose and evaluate a technique for instrumental variables estimation of linear models with conditional heteroskedasticity. The technique uses approximating parametric models for the projection of right hand side variables onto the instrument space, and for conditional heteroskedasticity and...

We propose and evaluate a technique for instrumental variables estimation of linear models with conditional heteroskedasticity. The technique uses approximating parametric models for the projection of right hand side variables onto the instrument space, and for conditional heteroskedasticity and...

We apply a new estimator to the measurement of the economic returns to education. We control for endogenous education, unobserved ability and measurement error using only the natural heteroscedasticty of wages and education attainment. Our prefered estimate, 6.07%, is closer to the OLS estimate...

Global production sharing is determined by international cost differences and frictions related to the costs of unbundling stages spatially. The interaction between these forces depends on engineering details of the production process with two extremes being 'snakes' and 'spiders'. Snakes are...

In this paper, we use a unique dataset on the distribution of output and demand across regions of the United States to estimate trade costs for 969 service and manufacturing industries. Our estimation method is a natural extension of the gravity model of trade and identifies trade costs in the...

This paper investigates the relation between a firm's location and its corporate finance decisions. We develop a simple model where being located within an industry cluster increases opportunities to make acquisitions, and to facilitate those acquisitions, firms within clusters maintain more...

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...