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...

Modern metropolitan areas involve large concentrations of economic activity and the transport of millions of people each day between their residence and workplace. We use the revolution in transport technology from the invention of steam railways, newly-constructed spatially-disaggregated data...

In this paper, we examine the effect of changes in population density--urban sprawl--between 1970 and 2000 on BMI and obesity of residents in metropolitan areas in the US. We address the possible endogeneity of population density by using a two-step instrumental variables approach. We exploit...

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...

This paper develops a model of the geographic distribution of crime in an urban area. When the police protect some neighborhoods (concentrated protection), the city becomes segregated. When the police are evenly deployed across the city (dispersed protection), an integrated city emerges. Unequal...

Mortality was extremely high in the industrial cities of the 19th century, but little is known about the role played by pollution in generating this pattern, due largely to a lack of direct pollution measures. I overcome this problem by combining data on the local composition of industries in...

In many cities, restaurants and retail establishments are spatially concentrated. Economists have long recognized the presence of demand externalities that arise from spatial agglomeration as a possible explanation, but empirically identifying this type of spillovers has proven difficult. We...

We examine how the spatial and social proximity of inventors affects knowledge flows, focusing especially on how the two forms of proximity interact. We develop a knowledge flow production function (KFPF) as a flexible tool for modeling access to knowledge and show that the optimal spatial...

I study the impact of transportation on health in the rural US, 1820-1847. Measuring health by average stature, I find that greater transportation linkage, as measured by market access, in a cohort's county-year of birth had an adverse impact on its health. A one-standard deviation increase in...