Don't forget that in Europe, population growth is fairly stagnant. Most of Western Europe would be experiencing population declines without massive immigration, and the problems that brings to these previously homogenous societies. The United States is still experiencing rocketing population growth. Here, where the the land is cheap cheap, sprawling suburbs are both the cheapest (short-term) way to put roofs over heads. Density i good, but here in SC, where undeveloped land can be less than $1000/acre and is usually around $2000/acre, it's hard to justify paying for that $3M/5 Acre in the inner burbs. Much cheaper to move out from the center. Besides, noone really works in the city anymore anyways.
