The boundary discontinuity method of causal inference may yield misleading results if a policy's impacts do not stop at the border of the implementing jurisdiction. We use geographically precise longitudinal employment data documenting worker job-to-job mobility to study policy spillovers in the...

In applied historical research, geographic units often differ in level of aggregation across datasets. One solution is to use crosswalks that associate factors located within one geographic unit to another, based on their relative areas. We develop an alternative approach based on relative...

We study the spatial expansion of banks in response to banking deregulation in the 1980s and 90s. During this period, large banks expanded rapidly, mostly by adding new branches in new locations, while many small banks exited. We document that large banks sorted into the densest markets, but...

We provide an in-depth study of short-term rental (STR) regulation in Chicago. While many municipalities choose between outright bans or laissez-faire strategies concerning STR activities, Chicago pioneered a middle-ground ordinance, enabling the market to exist with limitations and...

We examine "agglomeration shadows" that emerge around large cities, which discourage some economic activities in nearby areas. Identifying agglomeration shadows is complicated, however, by endogenous city formation and "wave interference" that we show in simulations. We use the locations of...

We measure the importance of increasing returns to scale and trade in medical services. Using Medicare claims data, we document that "imported" medical care -- services produced by a medical provider in a different region -- constitute about one-fifth of US healthcare consumption. Larger regions...

We study the history and geography of wealth accumulation in the US, using newly collected historical property tax records since the early 1800s. The US General Property Tax was a comprehensive tax on all types of property (real, personal, and financial), making it one of the first "wealth...

National industrial concentration in the U.S. has risen sharply since the early 1980s, but there remains dispute over whether local geographic concentration has followed a similar trend. Using near population data from the Economic Censuses, we confirm and extend existing evidence on national...

A key reason for the existence of cities are the externalities created when people cluster together in close proximity. During Covid, such interactions came with health risks and people found other ways to interact. We document how cities changed during Covid and consider how the persistence of...

We introduce new measurement tools to understand the sources of earnings differences across space. Based on the natural language employers use in job vacancy text, we develop granular measures of job tasks and of worker specialization. We find that jobs in larger commuting zones involve greater...