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...

Comprehensive zoning is ubiquitous in U.S. cities, yet we know surprisingly little about its long-run impacts. We provide the first attempt to measure the causal effect of land use regulation over the long term, using as our setting Chicago's first (1923) comprehensive zoning ordinance. Our...

Recent work has argued that zoning is responsible for racial segregation, disparities in public goods provision, growing regional inequality, and exploding housing costs in productive areas. However, the slow-moving nature of land regulation's effects suggests a crucial need for historical...

We study the urban structure of the City of Detroit. Following several decades of decline, the city's current urban structure is clearly not optimal for its size, with a business district immediately surrounded by a ring of largely vacant neighborhoods. We propose a model with residential...

One of the most important representations of an urban spatial structure is its density. Indeed, an urban area is defined as a densely populated place with a sizeable number of inhabitants. Yet, despite the fact that the defining element of an urban area is its density, few scholars have...

In 1956, 52% of urban men and 42% of rural men smoked cigarettes. By 2010, the disparity had flipped: 24.7% of urban men and 30.6% of rural men smoked. Smoking remains the greatest preventable cause of mortality in the United States, and understanding the underlying causes of place-specific...

The economic approach to cities relies on a spatial equilibrium for workers, employers and builders. The worker's equilibrium implies that positive attributes in one location, like access to downtown or high wages, are offset by negative attributes, like high housing prices. The employer's...

U.S. county data for the last 20 or 30 years show that manufacturing employment has been deconcentrating. In contrast, the service sector exhibits concentration in counties with intermediate levels of employment. This paper presents a theory where local sectoral growth is driven by technological...

We rely on a decomposition of employment changes into job creation and job destruction components - and a novel set of identifying restrictions that this decomposition permits - to develop new evidence about the driving forces behind aggregate fluctuations and the channels through which they...