For the first time in modern history, living with parents has overtaken other living arrangements for 18-34-year-olds, according to a Pew Research Centre report released today.
In 2014, 32.1 per cent of young adults lived in their parents' homes, edging out all other living arrangements, including marriage or cohabitation, living alone, or living as single parents or with roommates.
The change is fuelled by a steep decline in the portion of young Americans settling down romantically over the past 50 years.
Since 1880, when the Census Bureau started keeping track, the most common arrangement for young people was to live with a spouse or significant other. That peaked in 1960, when 62 per cent of 18 to 34-year-olds did so. Now, that number has fallen by half, with just 31.6 per cent living with a romantic partner.
Along the way, the median age of first marriage has risen steadily, from a 1956 low of 20 for women and 22 for men to 27 for women and 29 for men in 2014.
"For earlier generations of young Americans, one of the major activities that they were focused on was partnering, forming a new family, maybe with children," said Richard Fry, the study's author.
"For the first time, instead, what we see is they're not focused on family and forming a household." Rather, they are more likely to be tending to studies and work, hoping to earn and save enough to move out on their own.
A big reason is a decline in economic opportunities. As the cost of living has escalated and wages have stagnated, young people face mounting student debt and daunting barriers to renting or owning a home, creating obstacles to cohabitation and marriage.
The trend is led by young men, whose fortunes have been declining since the 1960s. While they have always lived with their parents in greater numbers than young women, this setup became the dominant living arrangement for them in 2009. In 2014 35 per cent of young men lived with parents, while only 28 per cent lived with a spouse or partner (for young women, the percentages are flipped: 29 and 35, respectively).
"For the typical young man over the last few decades the job market has worked against them," Fry said. Unemployed young men are more likely to live with their parents than those with jobs, and employment among young men has dropped significantly in recent decades.
A couple of years ago, Marshall Taliaferro, 25, took up residence in his parents' house in Leesburg, Virginia.
"I moved in with my parents because I don't really have to pay rent and I get free meals," said Taliaferro, who works in his father's advertising agency and at a local concert venue.
The setup is far from what he dreams of for himself.
"My ideal life is to be married, with maybe a kid or two, and at that point I would not be living with my parents; I would be living with my wife or girlfriend and bank account that I can live off of, and substantial enough pay. No parents would be lovely."
The trend towards living with parents is also more pronounced among minorities, the study found, with 36 per cent of black and Hispanic youth doing so.
But even among whites, the change since the 1960 was stark - from 19 per cent living with parents then to 30 per cent in 2014.
Philip Cohen, a sociology professor at the University of Maryland, said the study signals an important demographic milestone.
"I see this as part of an overall trend in an increase in family diversity and decline in the nuclear family household," he said.
It also reflects a change in young women's expectations and prospects, he said.
"Young women really don't want to be dependent on a man they're going to marry, and also they think they might have a better selection" if they wait until their careers are launched, he said. They may be right: "A large number of men say they want a wife who is a major financial contributor to the household," Cohen said.
Karla Caraballo-Torres, 25, and her boyfriend have lived on and off with her mother in Falls Church, Virginia, since graduating from college. They plan to move out of their Arlington apartment next week and back in with her mother (a third roommate is also moving back with his parents).
"When we've been living on our own we haven't been able to save," Caraballo-Torres said. A producer at a news station, she hopes to go to graduate school, and her boyfriend wants to travel, so moving to her mother's made sense.
Still, she feels hesitant.
"There was something of like, 'I have a full-time job, I should be able to live on my own," she said. "Ideally [living with her mother] wouldn't be the case, but realistically this is our best option."
A large number of men say they want a wife who is a major financial contributor to the household
The study found that people with lower education levels are more likely to be living with their parents rather than with romantic partners, while more highly educated young people are more likely to live with romantic partners.
That does not surprise Cohen. "Marriage has declined faster for people with low levels of education, and that has a lot to do with their ability to attain the kind of economic security to make them feel able to settle down and be excited to do so."
For them, cohabitation is not necessarily a one-way street, he said - it may be beneficial to the parents too, especially as middle-aged people are less likely to own their homes now than 20 or 30 years ago.
"The care and support flows up and down the generations, especially among poorer people," he said. "Now it's more likely that both generations are economically insecure and they're taking care of each other."
The trend towards moving back in with parents, which predates the 2009 recession, has significant economic and demographic implications, Fry said.
People who delay starting families could face fertility challenges down the road, he said. And in the near term, "The spending that goes on in the formation of a household - the furniture purchases, the appliance purchases, the cable subscriptions, that isn't happening."