You may not think the two things are related, but you'd be wrong. I devote a whole chapter to this in Why I Walk, and how living in a walkable place is better for your personal finances. Two years ago I blogged about this in a piece called, "Beware the 18%." Derek Thompson writes in The Atlantic in detail on the latest numbers:
This monopoly of housing/transit dominance is sticky for many reasons—America is big and has space for houses but zoning often limits development, leaving us with high relative housing prices and rents; suburban sprawl invites car ownership; infrastructure supports a car culture; our gas taxes are low and mortgage interest deductions are high; the list goes on—but it doesn't have to be this way. Not every country spends half its income on homes and cars. They have other priorities, like the UK, where the typical family spends a walloping 20 percent of its income on the super-category of "fun stuff": culture, entertainment, sports, alcohol, and tobacco. Or look at Japan, which spends more than twice as much as us on food consumed at home.
Well, I'm not sure it's that simple. First off, it's not at all surprising that as people make more money they buy a nicer place to live and spend more on transportation. Those are pretty basic human impulses. And I don't think it's fair to compare us to Japan - an island nation that has expensive food because it imports nearly everything.
On the larger points, though, the piece is right on. We spend a great deal more on transportation especially than we need to. And, that's not because we love cars, it's because of how we've planned our cities in towns so that we *need* cars to survive. The Italians and Germans also love cars, but they didn't destroy their cities and towns and build their entire lives around them.
The human impulse for being social is also very strong, and we simply need to account for that in American cities - it's what we lack more than anything else. The informal, easy social life that you have in a walkable place is what more and more people are craving. The desire to have a cave of your own is completely natural, but so is the desire to leave the cave, watch other humans and mingle. We call that urbanism (or urbanity) and that's what we need to do a better job of creating.