Cities make it easier for humans to interact, and one of the main advantages of dense, urban areas is that they facilitate social interactions. This paper provides evidence suggesting that the resurgence of big cities in the 1990s is due, in part, to the increased demand for these interactions...

New York has been remarkably successful relative to any other large city outside of the sunbelt and it remains the nation's premier metropolis. What accounts for New York's rise and continuing success? The rise of New York in the early nineteenth century is the result of technological changes...

The downsides of density, including traffic congestion, contagious disease and crime, were common in Victorian London and classical Rome, just as they are today in Sao Paulo and Lagos. Our urban past provides lessons for developing world cities today. The first lesson, that I highlight, is that...