Thursday, October 05, 2006

The 0.63 percent solution

Sprawl is wasteful. That's the mantra that has launched a thousand papers, editorials, speeches, conferences, books, etc. Too bad that no one bothers to define sprawl or waste.

Some relief is offered by Marcy Burchfield and her co-authors in the May 2006 Quarterly Journal of Economics, where they write about the "Causes of Sprawl: A Portrait from Space."

From their abstract: "We study the extent to which U.S. urban development is sprawling and what determines the differenecs in sprawl across space. Using remote-sensing data to track the evolution of land use on a grid of 8.7 billion 30x30 meter cells, we measure sprawl as the amount of undeveloped land surrounding an average urban dwelling. The extent of sprawl remained roughly unchanged between 1976 and 1992, although it varied dramatically across metropolitan areas. Ground water availability, temperate climate, rugged terrain, decentralized employment, early public transport infrastructure, uncertainty about metropolitan growth and unincorporated land in the urban fringe all increase sprawl."

If one is going to quibble about endogeneity, then decentralized employment would come first.

That aside, their data show the state-by-state increase in nonurban land urbanized; for all of the U.S., it was 0.63 percent over the period studied.