Freakonomics is hosting an interesting discussion about the future of cities which includes some very smart people. The responses range from sensible and enlightening to totally nuts, but it’s worth checking out. In general, I’m quite sanguine about the future of cities (shock!). I believe that the cost shifts we can expect to see in the new few decades will emphasize efficiency, to the good of central cities. Smaller homes will enjoy cost advantages in energy use over large ones, short trips will gain relative to long ones, and walking and mass transit use will gain relative to driving. I don’t anticipate massive shifts from suburbs to center cities, mind you, but I expect that price trends will slow exurban growth (and make it more dense and mixed-use) while feeding growth in central cities and inner suburbs. The better a city has done preparing an efficiency-oriented infrastructure, the more it will benefit from these cost shifts.
I do think that dramatic migrations could be in store for some cities in environmentally marginal areas. Metros in very dry, or fire-prone, or low-lying areas will probably face a more dramatic shift in cost pressures (particularly if struck by catastrophe). I don’t believe that we’ll be seeing much growth a decade from now in southern Florida or in the desert southwest.