American technological creativity is geographically concentrated in areas that are generally distant from the country's most persistent pockets of joblessness. Could a more even spatial distribution of innovation reduce American joblessness? Could Federal policies disperse innovation without...

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...

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...