WHY ARE CITIES growing faster than the rest of the country? That’s happening and reverses a decade-long trend, according to new U.S. Census figures. Gainers in 2008 included such diverse cities as Chicago, Columbus, Ohio, Lincoln, Neb., and Los Angeles. The Census found that cities losing people, such as Cleveland, were shrinking at a slower rate.

(With an 8.2 percent increase in people, New Orleans was the fastest-growing city, but is, of course, a special case. Its current population of 312,000 people remains 173,000 below the pre-Hurricane Katrina level.)

Will this development last? There are two explanations for it. One would suggest this phenomenon is temporary, the other not. Under the first, the economic crisis is trapping urban families that would otherwise head for the suburbs. Some can’t sell their current home and some can’t find jobs in a new place. An economic turnaround would free them up for the move out of town.

But there’s another possible reason, a trend away from the McMansion style and toward the urban amenities of shorter commuting times and downtown bustle. Feeding that theory are the population jumps in close-in suburbs, such as Arlington, Va., right outside Washington, D.C.

Aside from any swelling interest in museums or quirky shops, there are changing demographics. The nation is aging. Older Americans may prefer smaller living quarters, plentiful in urban areas, and having an alternative to driving.

My elderly father lives in a city apartment building with several residents over 90. (One woman — I do not lie — is 105 and recently went on a bus tour of Philadelphia with her caregiver.) If older people are in decent shape, they can live independently for a long time in an apartment. Cities provide lots of would-be helpers, some professional, some just neighborly.

My father’s building has an elevator, so no one has to negotiate stairs. There are restaurants and groceries within an easy walk. Anyone who has to go some distance can take a bus or get a cab. Meanwhile, restaurants deliver meals. And in the event of a medical emergency, excellent hospitals stand nearby.

My father’s cultural activities, basically watching television, could be as easily done on the range in eastern Montana. But when in the mood, he can join the lively street life right outside the building’s front door.

For younger Americans, work will play a big part in where they live. You have to wonder whether far-flung suburbs can restore their economies anytime soon, because so many of their jobs were tied to easily obtained mortgages, home construction and retail.

And me? I live in a leafy city neighborhood that could easily pass for an inner suburb. I drive places, but don’t have to drive everywhere and for everything. A spike in gasoline prices wouldn’t take a major chunk out of my budget. Those things please me.

However, I also love rural areas and their small towns. Country people who do country things and are part of their community also do fine.

The more difficult arrangement would seem to be spread-out, big-house living. It requires a high consumption of time, as well as of fossil fuels. And commuting on congested two-lane roads can be stressful. Then again, I know people who would not want to live any other way.

“Suburban sprawl may not be dead, but it’s certainly on hiatus,” the Population Reference Bureau’s Mark Mather told the Associated Press.

We shall see. Some day the dark economic clouds will lift, and people will be able to sell their houses at an acceptable price. Energy prices might come down, as well. Only then will we know the real story behind the surprising Census numbers.

Froma Harrop is a member of The Journal’s editorial board and a syndicated columnist.