We develop a general equilibrium geographic framework to characterize the welfare effect of transportation infrastructure investments. We tackle three distinct but conflating challenges: First, we offer an analytical characterization of the routing problem and, in particular, how infrastructure...

In this note, we consider a broad class of network models where a large number of heterogeneous agents simultaneously interact in many ways. We provide an iterative algorithm for calculating an equilibrium and offer sufficient and "globally necessary" conditions under which the equilibrium is...

We develop a versatile general equilibrium framework to determine the spatial distribution of economic activity on any surface with (nearly) any geography. Combining the gravity structure of trade with labor mobility, we provide conditions for the existence, uniqueness, and stability of a...

What do recent advances in economic geography teach us about the spatial distribution of economic activity? We show that the equilibrium distribution of economic activity can be determined simply by the intersection of labor supply and demand curves. We discuss how to estimate these curves and...

How does the interplay of geography and political-economic forces affect the shape of nations? This paper presents a quantitative framework for characterizing the equilibrium evolution of national boundaries in a world with a rich geography. The framework delivers simple equilibrium conditions...

We consider a model in which monetary policy is governed by a Taylor rule. The model has a unique equilibrium near the steady state, but also has other equilibria. The introduction of a particular escape clause into monetary policy works like the Taylor principle to exclude the other equilibria....

I develop a new theory of marketing costs and introduce it into a model of trade with product differentiation and firm productivity heterogeneity. In this model, a firm enters a market if it makes profits by reaching a single consumer there and pays an increasing marginal cost to access...

This paper studies the effects of marketing choice to firm growth. I assume that firm-level growth is the result of idiosyncratic productivity improvements with continuous arrival of new potential producers. A firm enters a market if it is profitable to incur the marginal cost to reach the first...

What are the economic impacts of a border wall between the United States and Mexico? We use detailed data on bilateral ows of primarily unauthorized Mexican workers to the United States to estimate how a substantial expansion of the border wall between the United States and Mexico from 2007 to...

How much of the spatial distribution of economic activity today is determined by history rather than by geographic fundamentals? And if history matters for the distribution, does it also affect overall efficiency? This paper develops a tractable theoretical and empirical framework that aims to...