Some parents dream of the day they come home to an empty nest.
That couldn't be more true for Mark and Christina Rotondo, who recently took their 30-year-old unemployed son to court to have him evicted from their two-story home in Camillus, New York, just outside Syracuse. Michael Rotondo had been living there rent-free for eight years, which may seem like a nightmare to many American parents.
On May 22 a New York State Supreme Court judge ruled in the parents' favor, ordering their son to pack his belongings and move out within three days. Michael Rotondo, who recently lost custody and visitation rights of his young son, had argued he needed six months to vacate, but the judge disagreed.
The court battle garnered media attention from across the nation, sparking a longstanding debate over how old is too old to be living under your parents' roof.
Nearly 55 percent of young adults, aged 18 to 24, still live at home in the United States, according to the U.S. Census Bureau. That percentage takes a nosedive for Michael Rotondo's age group -- the latest data shows just 16 percent of American adults aged 25 to 34 still live at home.
But when you look at the statistics in other countries, Michael Rotondo is in better company. In many cultures around the globe, living at home is more common and socially acceptable.
Since 2008, Europe has seen an overall drop across the continent in the number of adults still living at home. But the opposite is true for Italy, where the percentage has increased from 2014 to 2016, ABC News' Clark Bentson in Rome reports.
More than 65 percent of Italians aged 18 to 34 live at home with their parents, and nearly three quarters of them are men, according to the latest data from Eurostat, the statistical arm of the European Commission.
Italy has even coined a term for these men: "mammoni" or "mama's boys."
The strong bond between parent and child keeps many Italian men from moving out of their parent's home.
The lack of well-paying jobs, expensive living costs and the fact that Italians often finish their university degrees at a later age are other factors.
Middle East and North Africa
Young adults still living with their parents can be found across the Arab world, where familial bonds are highly valued.
In Egypt, it's customary for young adults to live with their parents until marriage, ABC News' Randa Ali in Cairo reports.
Alia, 26, of Cario, said there's a dynamic in Egyptian homes where you are still seen as a "kid" even if you are approaching 30. Young adults choose to live at home because it's "just how things are done" and it's not easy to go against the grain, she said.
"I live with my parents and would like to move out, but doing so would be seen as resentment toward home, which is not the case," Alia told ABC News. "Besides, it would be very draining in terms of arguments and could ruin my relationship with [my parents], which is something I value dearly and wouldn’t want to risk.”
“Even if, hypothetically, I was able to convince them," she added, "the move would put them and me under scrutiny from friend and family because it is an unorthodox situation."
Hossam, also 26, of Cairo, said he still lives with his parents because he has no other choice.
"I really want to leave. But they won’t understand, they will see it as disrespect after what they have done for me," Hossam, an engineer, told ABC News. "I also can’t afford to pay rent with what I am making now."
Hossam, whose three siblings also live at home, said he once tried to broach the sensitive subject of moving out with his parents.
"They said, 'If you want to leave, you walk out without the clothes that we bought for you,'" he recalled.
"I worked briefly abroad and the experience changed me drastically," Hossam added. "I am trying to travel again -- it is the only possible compromise -- but there are no work opportunities."
Waad, 27, of Alexandria, recently moved out of her parents' home and into an apartment of her own in Cairo. Her socially liberal family supported her decision to move, but Waad said she still struggled to find a place.
"Single, young people are often seen as cause for trouble. Some brokers had refused to work with me, saying that they only rent apartments to families or foreigners,” Waad told ABC News.
At one point, Waad said she signed an apartment lease that, in writing, barred her from having men over, which is a common but usually verbal condition set by landlords.
For 26-year-old Lamia in the nearby country of Jordan, the choice to live at home in Amman with her mother is her own, she said.
"If I want, I can find work outside Jordan or live alone inside Jordan," she said. "But this way is more comfortable. I don’t want to leave my mother alone, I like being by her side."
Many families in China reside in multi-generational homes. Traditionally, adult children live with their parents, and even grandparents, until they get married, ABC News' Karson Yiu in Beijing reports.
However, a 2017 study of nine countries by banking giant HSBC found that 70 percent of millennials in China were homeowners -- by far the highest percentage in any of the nations surveyed, including the United States, where 31 percent of adults aged 18 to 36 said they own their homes.
When the study's findings were released, Ralph McLaughlin, chief economist for real estate research firm Trulia, told Money that the concept of home ownership in China was different than in the United States. It's more than just owning a place to live.
There will be approximately 30 million more men than women on China's dating market by 2020. The gender imbalance means the competition for female partners is fierce. And since many Chinese parents only have one child, they often focus their efforts on boosting their child's prospects for getting hitched.
"Many Chinese families only have one heir thanks to the recently-abolished one-child policy," McLaughlin told Money. "Parents and grandparents will often pool their money together to invest in that child by buying a property in that child’s name."
But in Hong Kong, a whopping 76 percent of adults aged 18 to 35 still live with their parents, according to the Urban Research Group at City University of Hong Kong. It's hardly surprising; Hong Kong is one of the world's most expensive cities. The average cost for a typical apartment in Hong Kong is 74 percent higher than a comparable apartment in New York City.
In South Korea, adults who live with their parents are referred to as "kangaroos," ABC News' Joohee Cho in Seoul reports.
Although most South Korean adults aspire to be independent and live in their own homes, financial limitations prove to be a harsh reality.
The latest data from the state-run Korea Statistical Information Service shows that more than 30 percent of parents aged 60 and older in South Korea have children who still live at home. Over a third of these parents said their children cannot afford to live on their own, and more than 77 percent said they don't want their grown children to live with them.
A survey conducted this year by Shinhan Bank, one of the country's leading banks, found unmarried South Koreans who live with their parents earn less than those who live alone. Nearly 25 percent of 1,636 unmarried South Koreans surveyed said they are living with their parents for economic or financial reasons.