We examine portage sites in the U.S. South, Mid-Atlantic, and Midwest, including those on the fall line, a geomorphologic feature in the southeastern U.S. marking the final rapids on rivers before the ocean. Historically, waterborne transport of goods required portage around the falls at these...

In this paper we present and solve a three-stage game of entry, location, and pricing in a spatial price discrimination framework with arbitrarily many heterogeneous firms. We provide a unique characterization of all equilibria without imposing restrictions on the distribution of marginal costs

In markets where spatial competition is important, many models predict that average prices are lower in denser markets (i.e., those with more producers per unit area). Homogeneous-producer models attribute this effect solely to lower optimal markups. However, when producers instead differ in...

The "border effect" literature finds that political borders have a very large impact on relative prices, implicitly adding several thousands of miles to trade. In this paper we show that the standard empirical specification suffers from selection bias, and propose a new methodology based on...