Proving that he’s not entirely evil, the Washington Post’s Eric “War on Drivers” Weiss has put together a piece on shifting residential preferences in the wake of high gas prices. To his great credit, he lists some of the many, many ways that government created and perpetuated suburban growth. The idea that explosive sprawl is an entirely natural outcome of market processes is very wrong and very damaging.

Weiss gets an on-the-other-hand quote suggesting that residential patterns won’t change that much–that instead jobs will come to suburbanites, that households will economize on the many errands they run, and that the suburban vehicle fleet will grow ever more efficient. This point of view is also espoused by Ed Glaeser. I think all of those things will happen, and I also think the days of rapid suburban growth are over.

There are serious limitations on the extent to which some of these adjustments can be made. Weiss’ naysayer, a guy named Alan Pisarski, points to places like I-270, the Dulles corridor, and Tysons as examples of suburban job migration, but he doesn’t seem to get that despite their suburban orientation, those places are still employment concentrations. Employment sprawl can’t continue forever. Where will a big Tysons tech firm move to reduce its employees’ exposure to gasoline costs? Closer to suburban jobs? How is that even possible?  The only way to cut gas costs in such a case would be for the firm to locate near driving alternatives, or for its employees to locate closer to the firm.

In a similar vein, there are limits to how quickly and easily households can shift to more efficient vehicles. Those cars aren’t cheap or in infinite supply, and shifting preferences have sharply reduced the trade-in value of less efficient automobiles. And for marginal households, the need to shell out $30k for a new car may well be the difference between choosing to live in the far burbs and choosing to live closer in.

It also seems to me that computations of the additional cost of fuel price increases are seriously lacking. Most such calculations say look, if the average commute is this and the average fuel efficiency is this, then higher gas prices are only costing the average household $1,000 per year–chump change, really.

But actually, it’s not chump change. What’s more, that kind of calculation ignores a lot of important stuff. It doesn’t take into account non-commute driving. It also doesn’t take into account the fact that in low-density environments, all prices are heavily influenced by gas price increases. Home service professionals (everything from appliance repairmen to dog-walkers) in exurban areas are rapidly increasing their rates to adjust for higher driving costs. In a gas-intensive area more expensive gas affects the price of everything to a greater extent than in a walkable place.

And it’s important to recognize that all this economizing reduces the utility of a suburban place. If your typical errand runner now has to plan out a detailed errand schedule to minimize fuel use, then that’s a cost just like gas is a cost, and it reduces the value of suburban life. One of the great (supposed) advantages of suburban areas is convenience. If they cease to be convenient, they lose an advantage relative to denser places.

And finally, there are scale economies in neighborhoods. As central places grow and become denser, they become more vibrant, average tax burdens fall, retail options increase, and so on. As suburban places cease growing, then fewer retail establishments find it profitable to open. Residents have to drive farther to get to things they want or need, which adds still more to the suburban cost burden. And slower growth places significant stress on local budgets, forcing municipalities to jack up taxes (eroding yet another supposed suburban advantage).

I don’t know if we’ll see suburban slums. I think its a no-brainer that five years of oil prices at current levels will mean a significant shift in residential growth patterns.