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...

This paper uses data from 802,777 veterans assigned to 7,548 primary care providers (PCPs) within the Veterans Health Administration (VHA) to examine variations in the efficacy of primary care providers (PCPs), their consequences for health outcomes, and their determinants. Leveraging...

Although there is a large gap between Black and White American life expectancies, the gap fell 48.9% between 1990-2018, mainly due to mortality declines among Black Americans. We examine age-specific mortality trends and racial gaps in life expectancy in rich and poor U.S. areas and with...

We examine the impact of the opening of a new urgent care center (UCC) on health care costs and the utilization of care among nearby Medicare beneficiaries. We focus on 2006-2016, a period of rapid UCC expansion. We find that total Medicare spending rises when residents of a zip code are first...

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,...

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...