Empirical research on cities starts with a spatial equilibrium condition: workers and firms are assumed to be indifferent across space. This condition implies that research on cities is different from research on countries, and that work on places within countries needs to consider population,...

Are the well-known facts about urbanization in the United States also true for the developing world? We compare American metropolitan areas with comparable geographic units in Brazil, China and India. Both Gibrat's Law and Zipf's Law seem to hold as well in Brazil as in the U.S., but China and...

One of the most sustained uses of economic warfare by the United States occurred in Spain during WWII. We provide an overview of this episode based on the secondary literature and new research in the Spanish archives. We focus on three key battles: (1) an oil embargo against Spain in the summer...