We study entrepreneurship and growth through the lens of U.S. cities. Initial entrepreneurship correlates strongly with urban employment growth, but endogeneity bedevils interpretation. Chinitz (1961) hypothesized that coal mines near cities led to specialization in industries, like steel, with significant scale economies and that those big firms subsequently damped entrepreneurship across several generations. Proximity to historical mining deposits is associated with reduced entrepreneurship for cities in the 1970s and onward in industries unrelated to mining. We use historical mines as an instrument for our modern entrepreneurship measures and find a persistent link between entrepreneurship and city employment growth.

This paper uses decennial Census data to examine the residential integration of the foreign born in the United States between 1910 and 2000. Immigrant segregation declined in the first part of the century, but has been rising over the past few decades. Recent immigrants tend to hail from countries with greater cultural distinctions from U.S. natives, whether economic, racial, or linguistic. These factors explain much of the increase in segregation after 1970. Evidence also points to changes in urban form, particularly native-driven suburbanization and the decline of public transit as a transportation mode, as an explanation for the new immigrant segregation.

This paper uses data from the Census Bureau's Longitudinal Research Database to describe the dynamics of geographic concentration in U.S. manufacturing industries. Agglomeration results from a combination of the mean reversion and randomness in the growth of state-industry employment. Although industries' agglomeration levels have declined only slightly over the last quarter century, we find a great deal of movement for many geographically concentrated industries. We decompose aggregate concentration changes into portions attributable to plant births, expansions, contractions, and closures. We find that the location choices of new firms play a deagglomerating role, whereas plant closures have tended to reinforce agglomeration.