In the column that Dayo references below, Paul Krugman says:

Still, if we’re heading for a prolonged era of scarce, expensive oil, Americans will face increasingly strong incentives to start living like Europeans--maybe not today, and maybe not tomorrow, but soon, and for the rest of our lives.

Sounds about right. But Dayo goes even further:

[T]his is halfway stuff. Ideally, you’d want an urban infrastructure that reduced everyone’s work/play/life “commutes” to 20-minute walks, bikes and buses—if not shorter.

It seems to me there's an enormous difference between what Krugman's saying (if energy prices keep going up, people's lifestyle choices are likely to start changing in response) and what Dayo's saying, which I interpret to be that government should actively push people into higher-density lifestyles. What's wrong with government being neutral between various types of lifestyles? Maybe people will respond to higher energy prices by moving to cities--or maybe they'll decide they like suburban life enough that they're willing to buy smaller cars and spend a higher percantage of their income on transportation. Price genuine externalities as best you can, and let the chips fall where they may.

The reality, of course, is that government is nowhere close to being neutral between lifestyles. In a variety of ways (mortgage subsidies, huge highway budgets, minimal transit funding, restrictive zoning laws), the deck is heavily stacked in favor of low density. There's plenty that can be done to eliminate those distortions before you start going too far in the other direction. But it's always puzzled me why pro-urbanization liberals often insist on framing the debate by emphasizing the innate superiority of urban life. Under those circumstances, it's not hard to understand why some people are suspicious that the movement is less about environmental protection than about getting people to give up their cars and adopt a culturally "better" way of life.

--Josh Patashnik