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...

Long before economics turned to psychology, environmentalists were nudging and framing and pushing their cause like highly gifted amateur psychologists. Their interventions seem to have changed behavior by altering beliefs, norms and preferences, but because psychological interventions are often...

Using a sample of Harvard undergraduates, we analyze trust and social capital in two experiments. Trusting behavior and trustworthiness rise with social connection; differences in race and nationality reduce the level of trustworthiness. Certain individuals appear to be persistently more...

In recent years, comparative economics experienced a revival, with a new focus on comparing capitalist economies. The theme of the new research is that institutions exert a profound influence on economic development. We argue that, to understand capitalist institutions, one needs to understand...