Question Earthority!

“Urban sprawl is a phenomenon that many people love to hate. Surprisingly, there is little systematic evidence on how much sprawl there is or what causes it. Recent research by Burchfield et al. (2006) goes far in illuminating both of these issues. The authors base their definition of urban sprawl on the average proportion of land that is undeveloped within a kilometer of each building in a metropolitan area. More open space means more sprawl. Using high-altitude photographs spanning 1976 to 1992, the authors demonstrate that although commercial sprawl increased a bit over this period (primarily due to businesses joining consumers in the suburbs), there was no increase in the degree of residential sprawl—the proportion of undeveloped land around residences.” (09/06)