NEW YORK -- Nowhere else is living alone celebrated the way it is in Manhattan, where solo dwelling has been exulted in pop culture from "Seinfeld" to "Sex and the City."
But single living declined during the past decade in Manhattan, though it still is the nation's capital of single-person households. At the same time, living alone grew nationwide to an unprecedented level, particularly in parts of the West and South, according to an Associated Press analysis of 2010 census data.
Escalating rents during the last decade, as well as the perception that New York's most captivating borough is more family friendly than in years past, forced a dip in the rate in Manhattan -- from 48 percent of households in 2000 to 46.3 percent in 2010. Nationwide, the rate has reached an all-time high -- almost 27 percent of households.
Sociologists say long-term consequences of this phenomenon are showing already: Parents have less opportunity to influence who their children select as mates, resulting in more interreligious and interracial marriages. More seniors, especially women, are living by themselves into their later years. And planners and developers are figuring out how to accommodate the extra long-term demand for housing.
"I see the rise of living alone as one of the great demographic changes in modern history," said New York University sociologist Eric Klineberg, author of the soon-to-be-published "Going Solo: The Extraordinary Rise and Surprising Appeal of Living Alone." ''It may be the last great social change that we haven't fully come to terms with."
The biggest growth in solo dwelling has been in small communities such as Chattahootchee County, Ga., near Fort Benning, and Park County, Colorado, a result of other parts of the nation catching up with what had been a big-city trait. While some people initially are frightened by the prospect of living in solitude, others quickly find advantages.
Penny Jacobs was well aware of the extra resources required to live alone when she divorced her husband in 2003. But the 58-year-old attorney can tick off the advantages of solo living in her high-rise condo in downtown Orlando.
"You know that if you put something in the refrigerator, it will be there when you're ready to eat it. If your house is a mess, you know you made the mess. Nobody moves your stuff. The toilet seat is where you left it," Jacobs said. "I like the control, freedom and independence."
Record-high rents in the past decade contributed to the drop in single-person households in Manhattan, experts say. Rents averaging $2,000 a month for studios are forcing residents like Mathew Sanders, 27, and Mark Bonner, 29, to share an apartment on the Upper East Side into their late 20s and beyond.
The college buddies from Louisiana rent a one-bedroom, 700-square-foot "shotgun" apartment that requires Sanders to walk through Bonner's sleeping area to get to the front door. The living arrangement sometimes creates awkward moments, especially when it comes to dating potential girlfriends.
"Living in Manhattan is so irrational," said Bonner, an editor. "I came here with no job, but I grew up thinking that New York is the greatest city in the world. And if you're going to make a run at New York -- the dream -- you should live in Manhattan, in the heart of the city."
In the past decade, affordable housing has been squeezed by Manhattan landlords who are allowed to convert hundreds of rent-controlled and rent-stabilized apartments into market-rate units. There also has been a decline in the number of affordable apartments in many new buildings, said Zenaida Mendez, a longtime tenant organizer in Manhattan's Clinton neighborhood.
This West Side community had one of the borough's biggest declines in single-person households. It is home to many actors, musicians and stagehands who work in nearby Broadway and off-Broadway theaters and restaurants. Their incomes have shrunk because of the economic downturn and the use of taped music in Broadway shows, at a time when real estate agents estimate that residents need an income of at least $80,000 to live alone in Manhattan in a relatively attractive apartment.
"There are a lot of double-up families because of the lack of affordable housing," Mendez said. "People who come out of college and are making $45,000 and $50,000 cannot afford to rent a Manhattan apartment alone anymore, so two or three have to live together."
The perception that the borough is safer and the schools are better is contributing to families staying in Manhattan rather than moving to the suburbs, said Mitchell Moss, an NYU urban policy professor.
"You now see baby strollers and family dogs being walked even on Wall Street," he said.
Nationally, women are more likely than men to live alone. A major reason is that older women tend to outlive their male mates, and older men tend to marry younger women. For under-45 single dwellers, men outnumber women, mainly because women are more likely to live with their children than men, and women marry at a younger age than men, said Stanford University sociologist Michael Rosenfeld.
North Dakota had the highest percentage of solo living of any state -- 31.5 percent. It also had the highest percentage a decade earlier, but this time the reason is different. A decade ago, when the rate was 29.3 percent, young adults were moving from North Dakota to other places for better job opportunities, leaving behind a population of elderly residents who lived by themselves after their spouses passed away.
This time, an oil boom is transforming the western part of the state and attracting thousands of single, male workers who have left families behind, said Richard Rathge, a demographer at North Dakota State University.
Utah had the nation's lowest rate of solo living at 18.7 percent, a result of the dominance of Mormon culture that emphasizes marrying early and having children.
The biggest decline among states in the last decade was in California, particularly in the Inland Empire counties -- likely the result of higher rents and California's growing population of Hispanics and Asians, experts said.
The current rate of Americans living alone is unprecedented in U.S. history, as solo dwelling has been frowned upon for most of the nation's history, Rosenfeld said. In the Colonial era, it was even illegal for someone to live alone.
For most of American history, people would move out of their parents' homes only after they got married. But the rise of college-bound young adults in the 1960s, coupled with rising American mid-century affluence and a labor force opening to women in the 1970s, helped create a new life stage of independent living.
"Fifty years ago it was going to be really difficult for a woman to support herself," Rosenfeld said. "If you didn't want to live with your parents anymore, you needed a husband to take you away."
The growth of single, independent living away from parents has led to more interracial and interreligious marriages, as well as same-sex partnerships, Rosenfeld said.
"If you're living with your parents, the parents have ample opportunity to dissuade you from taking up with someone from a different religion or a different race or a different ethnic background or somebody who they think is inappropriate," he said. "But if you're living on your own ... then they don't really have any say in the matter, and it has changed the way the mating system in the United States works for young people."