For the last three months, Rob Agrawal has been ducking out of work early. Twice a week the 23-year-old software engineer and a college pal have spent happy hour laying waste to all comers at a nearby pub's "Beer Pong or Die!" tournament. Now the pair has first prize in sight: a keg of Miller High Life, delivered right to their doorstep. Exactly which doorstep that'll be is more complicated. "When we got to the finals, we had to tell the bar where we wanted the keg delivered," Agrawal says. "My buddy and I looked at each other, kind of saying, `Your parents cool with finding this baby on ice in the tub?'"

In Agrawal's case, probably not. His mother thinks a GMAT-prep course is to blame for her son's recent absences from the dinner table. It's a conclusion she jumped to herself, Agrawal explains, but he hasn't set her straight. When it comes moving home after college, he says: "The first rule is, don't ask, don't tell."

As far as rules go, that's not so bad, considering the alternative would mean paying rent. An estimated 4 million twenty-somethings have returned to the nest since 2007, according to the Pew Research Center, and almost all say that money — or, specifically lack of it — is the reason. Today a whopping one in eight people ages 22 to 29 has moved home because of the recession. Indeed, 70% of those who live with their parents are under 30. And why not? It's more comfortable. It's cheaper. It's got homemade lasagna and free laundry. And, ostensibly, it also allows recent graduates to save tons of money with which to, someday, move out.

Since this great migration began, many boomerangers might find that saving up — and moving out — is not as easy as they thought. Though it seems like a perfect scenario for shoring up one's finances — scoring a place to live with $0 in rent, and settling back in with parents who might bring some discipline (or, perhaps, even nagging) back into one's formerly independent life — that experience might also just increase discretionary spending, especially to get out of the house (staying home for Scrabble night with Mom again?). Soon, money that could be allocated toward rent or savings gets spent on shoes, or movie tickets, or beer pong. More than an economic necessity, living at home also can be a way to maintain a lifestyle that they grew up with. "Quality of life rose for middle-class families in the 1990s," says Dr. Patricia Cohen, a New York City-based family psychologist and mother of three twenty-somethings. "Most of our kids can't remember not having their own bathroom or vacations to Europe and the Caribbean."

Of course, almost no one I talked to for this story said living with mom and dad was ideal long-term, and with student loan debt, little if any savings, and grim job prospects, the economic obstacles are sizeable. Unemployment alone was above 20% for twenty-somethings in 2009. "My grandma jokingly calls me a lazy bum - I wish," says Jeff Merion, a 2009 college grad who has been looking for work since he moved back to his parents' house in St. Louis, Missouri, last year. "This is just reality for most of us."

The mom-and-dad savings plan

When Kate and Alex Archer moved back to Kate's hometown with their toddler, they planned to stay with Kate's parents for just a few weeks while they got settled. That was a year ago. There was just all that money they weren't spending. There were the mortgage payments they weren't making, the utility bills that didn't come and all the upkeep that goes with running a household. And when Alex considered the groceries Kate's parents buy and the free babysitting, "I'm happy to be a freeloader as long as possible," he says.

And no wonder: What the Archers aren't spending is substantial. According to Bundle data, people in their age group spend, on average, $325 on home improvement and home maintenance each month, another $298 on utilities and cable TV, and $411 on groceries. Add another $1,500 a month in mortgage payments, and that's a monthly savings of nearly $2,500 — no small chunk of change.

But there's a difference between "not spending" and "saving." A closer look and a little math reveals that many of the home-dwellers I spoke to aren't saving as diligently as they say. In the year since the Archers moved home, they've saved a total of about $7,500 — considerable, but still $5,000 less than their peers spent on home maintenance and groceries over the same time frame, and a lot less than the $30,000 in total savings from above. "Unfortunately, we'd already been living above our means for too long before we moved here," Kate Archer says. "I can't realistically imagine having $30,000 sitting in my bank account unused."

Similarly, Amy Brandt, a 26-year-old personal assistant who has lived in her parents' two-bedroom Manhattan apartment since 2006, has saved about $3,000 from her $30,000 annual salary. In comparison, other independent young New Yorkers spent three times that amount in home expenses — not even including rent. "Not paying rent definitely lets me splurge more," Brandt admits. "Fine, I haven't saved that much money, but at least I haven't gone into debt."

Where does the money go? The regular places, from law-school student loan payments and rising health insurance premiums to dinners out, a long weekend in Bermuda, or in Brandt's case, a weakness for designer shoes. In other words, they're spending just as their independent-living peers would, without the squeeze of the monthly bills. The only consequence is mom's disapproval. And hey, she'll come around.

Lost days of Ramen and roommates

After I graduated from college in 2001, I would have endured just about anything to avoid moving back in with my parents — and I did. Instead, to make ends meet on $22,000 a year in Boston, I stomached four male roommates, a disgustingly dirty apartment and a diet that consisted mainly of Ramen noodles. And so, frankly, did all of my friends. Eight years later, my youngest sister Maggie headed straight home after school. We share genes, the same bathroom growing up, even a closet affection for said Ramen. Why was she — and so many of her classmates — so ready to go home?

The dismal economy is absolutely part of it. But even in the eight years between my sister and me, there's been a generational shift in the way we relate to our parents. Today's twenty-somethings are remarkably close to their folks. As college students, they talked to their parents on average of 1.5 times a day, according to one study. And when mom and dad seem like older, wealthier pals who won't cramp your style, why not move home? In Seattle, Agrawal sheepishly confesses he could probably afford his own place by now. But then who would do his laundry, or clean the bathroom? His mom also still makes dinner most nights. "And I like it," he says. Brandt is more frank about why she still lives at home at age 26: "The idea of sharing a bathroom horrifies me." And though she'd never admit it, I think my sister misses our parents' housekeeper as much as she misses Mom and Dad now that she's living on her own in Brooklyn.

Parents, for the most part, understand this implicit bargain when their kids return home. And parents often have their own ulterior motives. "We tell ourselves that we're just easing their transition to adulthood, but I think my husband and I encourage it so we can hang on a little longer, too," says Sandy Barnes, whose 21-year-old twins will both be living at home by summer's end. Absent any financial strain, it can be an almost irresistible opportunity for some last-ditch parent-child bonding. And, frankly, to have an adult child who likes you enough to want to move back home? That's not a bad compliment, in the parental realm.

But the novelty, and the flattery, does wear off. On both sides. In Chicago, Bill Blockovich welcomed his son home two years ago, hoping the proximity would bolster their already close father-son bond. His son is still jobless (Blockovich didn't want to give his name in order not to hinder his job search) and shows few signs of leaving. Recently, Blockovich stepped in vomit as he came down for breakfast. "Immediately I wondered if I was doing him a disservice by letting him stay here," Blockovich says. "Then I wondered if I could still ground him."

Ah, but curfews are rare. Then again, so is dating. Even for a generation that is remarkably close to their parents, this is one area that remains awfully awkward. Annelise Searle, 23, lives at home so she can afford her low-paying-but-prestigious internship with the Minnesota Twins. Don't tell that cute guy in the striped shirt, though: When she and her other home-dwelling girlfriends go out, they occasionally pretend to be roommates. "It does feel like there is a stigma attached to living at home," she says.

And even for those who `fess up with their romantic prospects — well, then what? Last September Agrawal brought a girl home after a night out, only to find his father sitting on the couch at 2 a.m., waiting up. "My dad offered her ice cream, but it was definitely uncomfortable for all of us," he remembers. "The next morning is the only time he's ever asked when I planned to move out." The answer: Soon, Dad, soon.

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