Over the past decade or two, it’s been impossible not to notice the trend of people moving back into cities from the suburbs, and more recently, the rise of engineered walkable neighborhoods in suburban centers that emulate some of the best qualities of city life. Call it urban renewal if you like, or gentrification if you’re less sanguine about it, the trend is real and it’s certainly coming to a city near you.

The big question has always been what happens to people of lesser means to whom the city centers were abandoned in the second half of the 20th century. Renters will be leaving as their landlords cash in by selling their land for redevelopment, and rising property taxes insure that homeowners in poorer neighborhoods don’t stick around.

In the current Atlantic Monthly, Christopher Leinberger argues that they’ll be moving to the suburbs, or more likely, the exurbs. Just as mass abandonment of the city for suburbs created a huge stock of cheap housing, the reverse migration of people back into the city will leave plenty of houses that are suddenly extremely affordable. Here are some numbers:

Arthur C. Nelson, director of the Metropolitan Institute at Virginia Tech, has looked carefully at trends in American demographics, construction, house prices, and consumer preferences. In 2006, using recent consumer research, housing supply data, and population growth rates, he modeled future demand for various types of housing. The results were bracing: Nelson forecasts a likely surplus of 22 million large-lot homes (houses built on a sixth of an acre or more) by 2025—that’s roughly 40 percent of the large-lot homes in existence today.

Those houses are going to be the cheap rental properties of the future.

There’s definitely a lot more going on in the US housing market than the subprime collapse.