A large and growing share of international trade is carried on airplanes. Air cargo is many times more expensive than maritime transport but arrives in destination markets much faster. We model firms' choice between exporting goods using fast but expensive air cargo and slow but cheap ocean...

We develop a simple model of international trade with heterogeneous firms that is consistent with a number of stylized features of the data. In particular, the model predicts positive as well as zero trade flows across pairs of countries, and it allows the number of exporting firms to vary...

We explore the relationship between proximity of buyers and sellers and the organizational form of outsourcing. Outsourcing can be "contractual" in which suppliers undertake specific investments or involve "generic" market transactions. Proximity expands the variety of products sourced through...

In the automobile industry, as in many tradable goods markets, firms usually earn their highest market share within their domestic market. The goal of this paper is to disentangle the supply- and demand-driven sources of the home market advantage. While trade costs, foreign production costs, and...

In our European Economic Review (2002) paper, we used pre-1998 data on countries participating in and leaving currency unions to estimate the effect of currency unions on trade using (then-) conventional gravity models. In this paper, we use a variety of empirical gravity models to estimate the...

We study empirically technology diffusion across countries and over time. We find significant evidence that technology diffuses slower to locations that are farther away from adoption leaders. This effect is stronger across rich countries and also when measuring distance along the south-north...

Community traumatic events such as mass shootings, terrorist attacks, and natural or man-made disasters have the potential to disrupt student learning in numerous ways. For example, these events can reduce instructional time by causing teacher and student absences, school closures, and...

We study housing markets with multiple segments searched by heterogeneous clienteles. In the San Francisco Bay Area, search activity and inventory covary negatively across cities, but positively across market segments within cities. A quantitative search model shows how the endogenous flow of...

We study the role of distance and time in statistically explaining price dispersion for 14 commodities from 1732 to 1860. The prices are reported for US cities and Swedish market towns, so we can compare international and intranational dispersion. Distance and commodity-specific fixed effects...