This paper develops a new approach for measuring the stringency of a major form of land use regulation, building height restrictions, and applies it to an extraordinary data set of land-lease transactions from China. Our theory shows that the elasticity of land price with respect to the floor area ratio (FAR), a building height indicator, is a measure of the regulation's stringency (the extent to which FAR is kept below the free-market level). Using a national sample, estimation allowing this elasticity to be city-specific shows variation in the stringency of FAR regulation across Chinese cities. Single-city estimation for Beijing shows that stringency varies with site characteristics.

This paper identifies a new factor, the age of the housing stock, that affects where high- and low-income neighborhoods are located in U.S. cities. High-income households, driven by a high demand for housing services, tend to locate in areas of the city where the housing stock is relatively young. Because cities develop and redevelop from the center outward over time, the location of these neighborhoods varies over the city's history. The model predicts a suburban location for the rich in an initial period, when young dwellings are found only in the suburbs, while predicting eventual gentrification once central redevelopment creates a young downtown housing stock. Controlling for other determinants of where the poor live (e.g., proximity to amenities and public transit), empirical work indicates that if the influence of spatial variation in dwelling ages were eliminated, central-city/suburban disparities in neighborhood economic status would be reduced by up to 10 percentage points. Model estimates further predict that between 2000 and 2020, central-city/suburban differences in economic status will narrow in cities of all sizes, and especially in the larger metropolitan areas as American cities become more gentrified.

This paper provides empirical evidence showing the effect of airline cooperation on the interline fares paid by international passengers. The analysis focuses on two measures of cooperation, codesharing and antitrust immunity, and the results show that their partial effects are both negative. The presence of codesharing on an international interline itinerary reduces the fare by 8%–17%, with the exact number depending on the sample used and the estimation method. Moreover, the presence of antitrust immunity reduces the fare by 13%–21%. Codesharing and immunity are substitutes, however, in the sense that their combined effect is smaller than the sum of their partial effects. Taking account of this difference, which is captured by an interaction variable in the regressions, the combined effect ranges between 17% and 30%. These results provide strong evidence that airline cooperation in the fare-setting process generates substantial benefits for interline passengers.