WASHINGTON (AP) — Americans still want to own homes — if they can afford to. That's the finding of a report being released Wednesday by the Harvard University Joint Center for Housing Studies.

The pressures of student debt, rising rents and the leftover wreckage from the nearly decade-old housing bust have restrained people's ability to buy, even though the dream remains alive. The report sees reasons for both optimism (more millennials are poised to leave the nest) and concern (rising numbers of renters face extreme costs).

Those factors could determine whether the share of Americans who are renting keeps rising or whether the nation's home ownership rate can rebound from a near 48-year low of 63.5 percent.

Here are eight other major trends documented in the report:

___

MORE HOUSEHOLD FORMATION

Americans formed 1.3 million new households in 2015, a return to normal pace of growth. Household formation had floundered during the Great Recession and amounted to a paltry 653,000 in 2013. Much of last year's increase reflected an aging population in which more households consist of adults older than 65. But the Harvard analysis says the increase in households should continue because of the influx of millennials, which it defines as those born between 1985 and 2004.

During the recession and the sluggish recovery, many millennials returned to their childhood homes or lived with roommates, a trend that limited household formation. But as the largest generation in U.S. history, millennials are reaching an age when more of them will move out on their own. Millennial household formation is expected to average more than 2 million annually over the next several years, a surge that will likely further raise demand for rental units.

___

LARGER HOUSES, SMALLER APARTMENTS

Some people might love those tiny houses built on tractor trailers. But most yearn for extra space. The median size of a newly built single-family house was a record-setting 2,467 square feet last year. By contrast, the median unit in a new multifamily building has shrunk to 1,074 square feet from a peak of nearly 1,200 square feet in 2007. This decline likely reflects a shift in multifamily buildings away from condominiums toward rental apartments.

___

HOME BUILDING UP BUT STILL LOW

Homebuilders broke ground on 1.1 million properties last year, a healthy 10.8 percent annual increase from the depths of the recession. The problem is that figure still ranks among the worst years in the past half century. "In the long sweep of time, it's still a pretty small number," said Chris Herbert, managing director at the Harvard center.

Before 2016, apartment buildings, more than single-family houses, drove much of the increase in construction. But even as developers are stepping up single-family construction, they're focused less on increasing the number of homes and more on catering to a smaller pool of affluent buyers who can generate more profit per house.

___

HIGH RENT

The government considers renters who spend more than 30 percent of their incomes on housing to be "cost-burdened." Renters who spend more than 50 percent are considered "severely" burdened. The number of renter households that pay at least half their income reached a record 11.4 million in 2014, rising by 2.1 million from 2008 even as the economy began pulling out of the recession.

___

POOR DWELLERS CAN'T AFFORD FOOD

Compared with those who can find affordable housing, the poorest 25 percent of cost-burdened households spend on average 41 percent less each month on food. These same people also spend less on health care, not to mention retirement savings.

___

HOUSING AID ELUDES THE NEEDIEST

Just one fourth of income-eligible renters receive any kind of public assistance. The shortfall is the result of inadequate government support, Herbert said. It's true that the government can cut its housing expenditures by limiting its financial aid. But when people can't afford rent, it creates an unstable situation where evictions become more common.

Housing instability can often increase people's dependence on other social programs that raise costs for taxpayers in the long haul, Herbert said. It becomes harder to keep a job or learn in school when shelter is a constant uncertainty and increases dependence on other forms of welfare, he said.

"We can spend a little now, and in the end it's going to create people who are much more financially stable on their own," Herbert said.

___

CLUSTERS OF THE POOR

Between 2000 and 2014, the population in neighborhoods with poverty rates of at least 40 percent more than doubled to 13.7 million. That poverty overlaps with racial segregation. About 25 percent of poor blacks and 18 percent of poor Hispanics live in these high-poverty neighborhoods, compared with only 6 percent of whites.

___

AGING CONSTRUCTION WORKERS

The layoffs after the housing bust left builders with older construction crews. The share of building trades workers older than 55 rose to 16 percent from 10 percent in 2007. Just 13 percent of newly hired construction workers were under 25. Vocational training and immigration could help ease the coming labor shortage as older workers retire. So could opening up the industry to women, who make up less than 3 percent of construction workers.