Burdened by $85,000 in college debt, attorney Bobby Waltman lives with his mom and grandmother in a three-bedroom house in Huntington Beach, Calif.

Past frugality led the 29-year-old to live in a van parked at the beach, a one-room casita and a tent in Alaska. Now, he's counting the days until his finances are sound enough to afford a home of his own.

"I've had this plan to move out for a while, and it just keeps getting postponed," said Waltman, who works for a Newport Beach, Calif., personal injury firm. "I'm working at a really good firm and I'm still living at home, and I figure it's time I move on. [But] it's hard to take on a mortgage with law school debt."

Waltman may be symptomatic of a problem that's still plaguing the housing market — and, to some extent, the economy as a whole. The recession forced millions to move in with parents and relatives, or delay leaving, and to double up with roommates.

That means they put off buying a home or renting, and the impact has rippled through the economy in the form of reduced demand for furnishings, appliances and supplies.

Although job growth has returned and the housing market has improved, some economists worry that not enough young people are leaving the nest.

Whether it's because of student loans, credit card debt, a foreclosure hangover or a need to save for a mortgage, "household formation" has yet to get anywhere near prerecession levels.

The slow pace of household formation means fewer first-time buyers taking up that slack, which could limit the housing market going forward.

While the nation averaged nearly 1.2 million new households a year in the past five decades, that number fell to about 650,000 annually in the past five years, census figures show. Last year, 160,000 new households were created.

"During this past recession, household formation really got affected negatively because some of these kids lost their jobs and moved back with their parents, or they coupled up," said Chapman University economist Esmael Adibi.

But Adibi noted that some people — like his neighbor's 26- and 29-year-old children — still are living with their parents long after getting rehired. "You need more than job creation," he said. "You need job security."