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...

The great housing convulsion that buffeted America between 2000 and 2010 has historical precedents, from the frontier land boom of the 1790s to the skyscraper craze of the 1920s. But this time was different. There was far less real uncertainty about fundamental economic and geographic trends,...

America's local governments spend about one-eighth of our national income, one-fourth of total government spending, and employ over 14 million people. This paper surveys the large and growing economics literature on local governments and their finances. A primary difference between local and...

There are many possible ways of reforming the Government-Sponsored Enterprises that insure mortgages against default, including a purely public option, complete privatization or a hybrid model with private firms and public catastrophic insurance. If the government is sufficiently capable and...

To identify the determinants of social capital formation, it is necessary to understand the social capital investment decision of individuals. Individual social capital should then be aggregated to measure the social capital of a community. This paper assembles the evidence that supports the...

Does the economic model of optimal punishment explain the variation in the sentencing of murderers? As the model predicts, we find that murderers with a high expected probability of recidivism receive longer sentences. Sentences are longest in murder types where apprehension rates are low, and...

More than 17 percent of households in American central cities live in poverty; in American suburbs, just 7.4 percent of households live in poverty. The income elasticity of demand for land is too low for urban poverty to be the result of wealthy individuals' wanting to live where land is cheap...

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...

Do urban children live more segregated lives than urban adults? Using cellphone location data and following the 'experienced isolation' methodology of Athey et al. (2021), we compare the isolation of students over the age of 16--who we identify based on their time spent at a high school--and...