The fast and often chaotic urbanization of the developing world generates both economic opportunity and challenges, like contagious disease and congestion, because proximity increases both positive and negative externalities. In this paper, we review the expanding body of economic research on...

At the metropolitan level there is a striking negative correlation between residential racial segregation and population characteristics -- particularly for black residents -- but it is widely recognized that this correlation may not be causal. This paper provides a novel test of the causal...

Will improvements in information technology eliminate face-to- face interactions and make cities obsolete? In this paper, we present a model where individuals make contacts and choose whether to use electronic or face-to-face meetings in their interactions. Cities are modeled as a means of...

Historically coal has offered both benefits and costs to urban areas. Benefits include coal's role in fueling industry and thus employment. The primary costs are air pollution and its impact on human health. This paper starts by using a Rosen-Roback style model to examine how differences in...