RICK VAN KAMPEN has tried living on his own twice in the last four years. Now he's back where he grew up - in the same house, same room."You can't beat home cooking," says Mr. Van Kampen, a 25-year-old who is trying to save money to get married. He is not alone these days. Young Australians right through their 30s are now moving back in with "mum and dad." Instead of "empty nests," notes Robyn Hartley, a research fellow at the Australian Institute of Family Studies in Melbourne, there are new metaphors including "crowded nests" and the "never-empty nests." Social geographer Ron Horvath at the University of Sydney calls it the "revolving door," where sons and daughters routinely move in and out: "When we get together with friends, we ask 'Where in the revolving door are your children? Statistics compiled by the Australian Bureau of Statistics show how the revolving door has been speeding up. In 1990, 26.4 percent of the male population aged 20 to 34 lived at home, compared with 22.9 percent in 1981. The female population shows the same trend: In 1990, 16.3 percent of women aged 20 to 34 lived with their family, compared with 11.8 percent in 1981. A big reason why young adults are moving back home here - as well as in the United States, for that matter - is economic. "Some are studying full- or part-time, some are unemployed, some have not been able to establish themselves in a career," writes Ms. Hartley in the publication Family Matters. Jennifer Samuel, 26, for example, moved back into her parents' house in the Sydney suburb of Turramurra a year ago, after she enrolled as a full-time student at the University of Technology, Sydney. "I couldn't afford to live outside," says Ms. Samuel. She earns spending money by teaching aerobics classes. Her parents wanted to charge her rent, but she demurred. Instead, she cleans the kitchen and bathroom weekly. But even working Australians are living with parents. Adam McGrath, a 22-year-old New South Wales constable, still lives with his mother, Vicki Taylor, in Bondi Beach. "On his salary, he can't afford to live on his own," says Ms. Taylor, adding, m sure he would like to leave." David Martin, a 28-year-old schoolteacher, has moved back to his parents' Wahroonga house to save money. When he was renting an apartment, he had little money left over after his A$920 (US$726) rent, the car payments, and his retirement account. "I did not take into account how much it was going to take to set up a place. Paying off the furniture was a constant drain and I never had any money to do anything," he says. Martin's sister Catherine, 31, is also back - for her fifth or sixth time. A graphic artist, Ms. Martin works until she has enough money to travel overseas. "It usually means I give up the place I'm living," she says, so she moves back home. Such flux is more common these days, says social geographer Horvath, whose children are back for the fourth time. In the past, young people would have moved into less desirable urban areas. Today, some of these areas are trendy, and real estate speculation has absorbed a lot of the cheap housing. "Suddenly they are the top areas for development," says Don Burnard, a psychologist with the Family Information Center in Melbourne. Living at home does have its advantages - considering the services a loving mother can provide. Van Kampen mows the lawn, but his mother does the laundry and helps take care of his dog, Max. Taylor does the cleaning, laundry, and cooking for her son. "He does nothing - he has a wonderful mother," she says. Her son does buy all their food, though, which costs at least A$120 (US$94) per week. The cooking and cleaning is all worth it, says Frances Wootton, whose 23-year-old son Warren has been coming and going for eight years. "By coming home, they have the support of someone who loves them and cares, and that gives them the stability to stand on their own," says Ms. Wootton, a Bondi Beach resident. Whenever her son has moved out, Wootton has always left little messages for him: "I tell him I love him and the house is always there for him." The love, she says, has helped her son mature into "a very caring person."