At 22, Mallory Huston isn't living with her parents so she can sleep till noon, eat all the food and hog the television. She's a former high-school valedictorian, a well-spoken graduate of Capital University, an accountant for Ernst & Young and the fiancee of a law student. By choice -- not necessity -- she lives in the three-bedroom South Side ranch where she grew up.

For Huston's generation, living at home can be a financially desirable, socially acceptable option -- not the failure route of slackers too immature to live on their own.

"I don't think I've ever gotten a negative reaction to it," she said. "No one's ever said, 'That's terrible.' A lot of times, it's 'I wish I could have done that.' "

In 2007, 28 percent of 18- to 34-year-olds lived with their parents, according to the Network on Transitions to Adulthood, a research project paid for by the MacArthur Foundation. The figure represents a 25 percent increase since the 1960s, when children were often eager to leave home as soon as possible.

Parents and children are more likely to live together in an economic downturn, said Jordan Matsudaira, a Cornell University economist who has studied the correlation between employment levels and residences of young adults. But a weak job market accounts for just the occasional uptick, not a long-term shift. "I really don't think that the economic factors have contributed much to the long trends at all," he said. "I think it's much more a story about changes in social norms."