Hazel Morrow-Jones has spent much of a lifetime trying to answer a simple question: Why do we live where we live?

The question might be simple, but the answer isn’t — hence the decades of research.

Do we choose a home because it’s close to work or has a pleasing design? Because it’s in a safe neighborhood or a good school district? Near family or close to where we grew up?

The question isn’t merely academic. Finding the answer is vital to keeping our cities and older suburbs healthy, or else residents will push farther and farther away from the central city.

As a professor of city and regional planning at Ohio State University, Morrow-Jones knows the possible answers are endless. She also knows that buying a home is an extremely emotional and individual decision, and that no single study will explain every choice.

Despite the daunting possibilities, some broad conclusions can be drawn from Morrow-Jones’ 30-some years of researching the topic, and they present huge challenges for urban planners.

The short version: People like new and big homes far from the central city.

“The largest single reason people move is because their house isn’t the right size: Three-quarters need a larger home and a quarter need a smaller home.”

Crime, school quality and traffic matter but not as much as one might think.

“People have told us they were not leaving the central city because of the schools; the rating they gave the schools is largely the same that suburban households give when they leave,” she said.

But in both cases they do leave, and, through time, the pattern is clear: Homeowners leave the central city for the suburbs, and they leave the inner suburbs for the outer ones.

In central Ohio, Morrow-Jones notes, this migration is softened a bit by the unusual health of the five inner suburbs: Bexley, Grandview Heights, Upper Arlington, Whitehall and Worthington.

But the outward migration happens from those places as well.

In a recent study, Morrow-Jones and one of her students, Moon Jeong Kim, looked at those who sold a home in one of the five inner suburbs and bought another central Ohio home in the same year. They found that about 10 percent moved into Columbus. Of the rest, about half bought in the same suburb or another older one and half moved farther out.

In other words, about 45 percent of those who left those suburbs moved to a newer suburb farther from the central city.

The main reason they moved out: They wanted a larger house — and a newer one.

“Much as some of us romanticize old homes, a new house is a dream for someone who’s had problems with an old one,” Morrow-Jones said.

She has also found that homeowners on average prefer the car-centric suburban maze that urban planners despise over neighborhoods that emphasize walkability.

This presents a challenge for urban planners: how to keep or attract people to older areas of town.

One answer, Morrow-Jones suggests, is to encourage home construction in older neighborhoods or in infill lots.

“A new home in an old neighborhood — that’s the ideal. No one wants to deal with the old wiring, but they love the old trees; they love the character of the older homes and the access to things.”

Until that happens on a wide scale, Morrow-Jones thinks we should plan for our boundaries to continue to stretch.

“I find it interesting that people who move to the far-out suburbs don’t realize the city will follow them,” she said. “That outward trend will just continue. . . . Unless Dublin, for example, keeps annexing, it will have people leaving it, too, and the next one farther out, and so forth.”

Morrow-Jones (who, by the way, lives in a 56-year-old home in Upper Arlington) has seen lots of speculation about how the economy or environmental concerns or the “living small” movement will keep people from continuing to move to newer and bigger homes farther and farther away.

“I’ve seen a lot in the literature about how current problems, such as gas prices and the economy, will permanently change the way we view housing,” she said. “But I’m not convinced. It would have to last a lot longer than I suspect it will.”

Jim Weiker writes on home and real-estate issues. Reach him at 614-… or by e-mail.

jweiker@dispatch.com