Lots of bloggers are all over this one, so why not join the party?
The always-annoying John Stossel goes on TV to peddle the notion that urban sprawl is the natural result of the free market--and that urbanism, on the other hand, is the result of evil librul meddling in the high holy marketplace. Or somesuch.
And is promptly whacked at by two columnists from opposite sides of the political spectrum, The American Conservative's Austin Bramwell, and our good friend Yglesias.
Of course, I would be remiss if it weren't pointed out that it just isn't the zoning codes and such encouraging sprawl--the banking and finance industry has long been reluctant to finance construction of anything but. Wanna build a big box store with a parking lot the size of Texas? No problem, here's your money. Wanna build it downtown on a 200' x 200' city block, above a garage and next to a transit line? Sorry, the big guy upstairs considers that investment too risky.
I would also be remiss in pointing out that our forms of infrastructure and (sub)urban design carry a lot of inertia--the presence of lots of sprawl means lots of cars, and where's the most convenient place to park your car? More sprawl.