Should the national government undertake policies aimed at strengthening the economies of particular localities or regions? Agglomeration economies and human capital spillovers suggest that such policies could enhance welfare. However, the mere existence of agglomeration externalities does not...

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...

How effective are restrictions on mobility in limiting COVID-19 spread? Using zip code data across five U.S. cities, we estimate that total cases per capita decrease by 20% for every ten percentage point fall in mobility. Addressing endogeneity concerns, we instrument for travel by residential...

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,...

The pension landscape in the U.S. has changed dramatically over the past 25 years. Saving through personal retirement accounts has become the principal form of retirement saving. We document the transition from a defined benefit system to a personal account system and show the effect it has had...

Recent literature on the relationship between ethnic or racial segregation and outcomes has failed to produce a consensus view of the role of ghettos; some studies suggest that residence in an enclave is beneficial, some reach the opposite conclusion, and still others imply that any relationship...

In the past few decades, some measures of population risk have improved, while others have deteriorated. Understanding the health of the population requires integrating these different trends. We compare the risk factor profile of the population in the early 1970s with that of the population in...

Americans average 25.1 working hours per person in working age per week, but the Germans average 18.6 hours. The average American works 46.2 weeks per year, while the French average 40 weeks per year. Why do western Europeans work so much less than Americans? Recent work argues that these...

A free and informative press is widely agreed to be crucial to the democratic process today. But throughout much of the nineteenth century U.S. newspapers were often public relations tools funded by politicians, and newspaper independence was a rarity. The newspaper industry underwent...

The United States today, according to most studies, is among the least corrupt nations in the world. But America's past was checkered with political scandal and widespread corruption that would not seem unusual compared with the most corrupt developing nation today. We construct a "corruption...