We parents of college students had better get the basements fixed up. According to none other than Karl Rove and his political action group, chances are better than eight in 10 that the kids will be hauling themselves and their ratty belongings back home after graduation.

American Crossroads is out with a political ad that disses President Barack Obama for being “cool.” It shows him dishing with celebrities and quaffing a beer, and notes that “after four years of a celebrity president” half of college graduates can’t find jobs that fit their skills, student debt has topped $1 trillion and — OMG! — 85 percent of recent college grads have been forced to move in with their parents.

I don’t think this ad will phase college students, who tend to be optimistic about overcoming the obstacles mentioned. But parents, that’s a different story. Eighty-five percent of college grads moving back home? You can see a shudder moving through the land.

Parents can stand down, however. PolitiFact, the fact-checking service of the Tampa Bay Times, examined the claim and pronounced it false.

It turns out the 85 percent number is kind of a suburban myth, although widely reported on media outlets including Time, CNNMoney and the Huffington Post.

PolitiFact found the claim originated with a now-defunct consulting firm, Twentysomething Inc., whose managing director said the number came from a poll done “many years ago” for an undisclosed client. Not a claim you’d want to stake your reputation on.

A much more accurate picture of the so-called boomerang generation is found in a recent report by Pew Research Center, which did extensive polling of families in multigenerational situations, based on 2010 U.S. census data.

The Pew survey found that 39 percent of adults 18 to 34 said they either lived with their parents or had moved back in temporarily in recent years. Up to age 30, college graduates were as likely as non-college graduates to be living with the folks. After age 30, only 10 percent of college grads remained tied to their parents’ home, compared with 22 percent of adults ages 30 to 34 without a college degree.

The Crossroads group is correct that the number of young adults living with parents is up in the recent economic slump. Pew’s analysis found the highest incidence of multigenerational living since the 1950s.

But is that really an indication of a lost generation? Living with the parents after college isn’t exactly a new phenomenon. I did so for a couple of years, to save some money while working an evening reporting shift for a small newspaper. It wasn’t my first choice; that would have been a studio apartment in New York City. But the food was good, and my mom and I developed a mutual addiction to watching “All My Children” before I headed to work.

In the Pew report, most of the young people and parents surveyed reported being OK with cohabitation. Everybody pretty much got along and both generations reported financial benefits.

That tracks with what Traci Klasing sees in her job as assistant director of the career development center at Park University. Some graduates choose to move back home even if they have other options, she said.

“I don’t really see students fleeing from it,” she said. “To me, they’re embracing it.”

Remember, these are the families who caravanned together to endless soccer games and band competitions. Studies have shown that the young adults of Generation Y mostly have good relationships with their baby boomer parents. “They’re independent folks, but they really value their parents’ opinions and judgments,” Klasing said.

The boomerang effect isn’t just because college graduates want to bond with their parents, of course. Long job searches and low pay for entry-level jobs has a lot to do with it, as does debt. On those points Crossroads America hits a legitimate target, although Obama is making a campaign issue out of reducing student debt.

But the specter of moving home with the parents isn’t really scaring anybody. My personal view is that college graduates are better off living on their own. They achieve true independence and might learn how to cook. But I’m keeping my college sophomore’s room intact — just in case.

• Shelly is a columnist for the Kansas City Star.