Urban proximity can reduce the costs of shipping goods and speed the flow of ideas. Improvements in communication technology might erode these advantages and allow people and firms to decentralize. However, improvements in transportation and communication technology can also increase the returns...

Urban economists understand housing prices with a spatial equilibrium approach that assumes people must be indifferent across locations. Since the spatial no arbitrage condition is inherently imprecise, other economists have turned to different no arbitrage conditions, such as the prediction...

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...

When members of deliberating groups speak with one another, their predeliberation tendencies often become exacerbated as their views become more extreme. The resulting phenomenon -- group polarization -- has been observed in many settings, and it bears on the actions of juries, administrative...

Why do levels of entrepreneurship differ across America's cities? This paper presents basic facts on two measures of entrepreneurship: the self-employment rate and the number of small firms. Both of these measures are correlated with urban success, suggesting that more entrepreneurial cities are...

Are individuals more likely to smoke when they are surrounded by smokers? In this paper, we examine the evidence for peer effects in smoking. We address the endogeneity of peers by looking at the impact of workplace smoking bans on spousal and peer group smoking. Using these bans as an...

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 last 50 years, population and incomes have increased steadily throughout much of the Sunbelt. This paper assesses the relative contributions of rising productivity, rising demand for Southern amenities and increases in housing supply to the growth of warm areas, using data on income,...

Many industries are geographically concentrated. Many mechanisms that could account for such agglomeration have been proposed. We note that these theories make different predictions about which pairs of industries should be coagglomerated. We discuss the measurement of coagglomeration and use...

In the past two elections, richer people were more likely to vote Republican while richer states were more likely to vote Democratic. This switch is an aggregation reversal, where an individual relationship, like income and Republicanism, is reversed at some level of aggregation. Aggregation...