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...

A Melitz-style model of monopolistic competition with heterogeneous firms is integrated into a simple New Economic Geography model to show that the standard assumption of identical firms is neither necessary nor innocuous. We show that re-locating to the big region is most attractive for the...

How integrated are labor markets within a country? Labor mobility is key to the integration of local labor markets and therefore to understanding the efficacy of policies to reduce regional inequality. We present a comprehensive framework for understanding migration decisions, focusing on the...

In this paper we study the role of the transportation sector in world trade. We build a spatial model that centers on the interaction of the market for (oceanic) transportation services and the market for world trade in goods. The model delivers equilibrium trade flows, as well as equilibrium...

This paper models the relationship between countries' distance from global economic activity, endogenous investments in education, and economic development. Firms in remote locations pay greater trade costs on both exports and intermediate imports, reducing the amount of value added left to...

This paper reviews recent research on geography and trade. One of the key empirical findings over the last decade has been the role of geography in shaping the distributional consequences of trade. One of the major theoretical advances has been the development of quantitative spatial models that...

This paper develops a two-region, two-sector general equilibriun model of location. The location of agricultural production is fixed, but ionopolistcally competitive manufacturing finns choose their location to maximize profits. If transportation costs are high, returns to scale weak, and the...

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...

Historically, urban growth required enough development to grow and transport significant agricultural surpluses or a government effective enough to build an empire. But there has been an explosion of poor mega-cities over the last thirty years. A simple urban model illustrates that in closed...