For quite a while, we’ve been hearing about young people who graduate from college, fail to find a job and move back in with their parents – Boomerang Kids. Now there’s a new trend, and it’s just the opposite: old people who retire and follow their adult children to wherever they’ve moved to – Caboose Parents, to coin a phrase.

At least I hope I’ve coined a phrase. There’s nothing we columnists like better than dreaming up a catch phrase. I’ve always envied Tom Wolfe for dubbing the 1970s the Me Decade. No decade since has been so wittily named.

I count a number of Caboose Parents among people my age. They’re planning to relocate to some distant city where their children have settled down and started families. They’re not moving in with them – money isn’t a problem. They plan to buy a house nearby and “spend time with the grandkids.”

I admit I feel a bit resentful. I’m going to be seeing a lot less of these friends. It’s especially annoying when they’re abandoning St. Louis for some city I consider much less attractive. One cherished former colleague is moving to Phoenix. No offense to Phoenicians, but the only good thing I can see about living in Phoenix is that you can call yourself a Phoenician. You have to put up with summers even longer and hotter than St. Louis’s, and for your drinking water you have to depend on engineering miracles and miles of pipeline. But there’s no arguing against the pull of grandkids.

For baby boomers like me, this new trend takes some getting used to. Our parents didn’t follow us when we moved away. Frankly, we wouldn’t have wanted them to. These were the days of the Generation Gap (another great catch phrase), when the political battles of the ’60s opened a chasm between parents and their children. A typical day at home would begin with a father asking his son, “So what are your plans for today? Are you going to get a haircut, or are you going to join the Communist Party?” And it would go downhill from there.

As a grownup, you could forgive and forget such quarrels, but still believe that distance was good for your relationship with your parents. My contemporaries have had much more harmonious relationships with their children, and that’s a welcome development.

Other improvements have also helped make it easier for parents to stay close to adult children. A couple I know recently flew to the Pacific Northwest to help their daughter move to a new apartment. We boomers wouldn’t have dreamed of asking our parents for such a favor. But joint replacements and frequent flyer miles make it feasible.

Back then, in fact, people were pretty worn out by the time they retired. Assuming their Golden Years would be few in number, they mostly did one of two things: keep the family home and welcome the kids back for the holidays, or move to a retirement community in Florida and play golf.

Caboose Parents are making a different choice, but it isn’t exactly a new one. We’re seeing a reappearance of a very old model of family life, the multigenerational household. Today’s grandparents don’t live in the same house with their offspring, but they’re close enough to come over often.

Why are families pulling together? Possibly because the future looks ominous. With society becoming politically polarized, technology getting out of control and the consequences of global warming looking more undeniable and unavoidable every day, people want to stick close to their nearest and dearest.

A more cheerful explanation is also possible. Thanks to medical advances, people who retire today can look forward to longer, more active lives. The Golden Years become Golden Decades. Grandparents feel young enough to move to a new city. They anticipate close involvement in the lives of their grown-up children (“The nicest people you’ll ever meet,” says devoted dad Bill Murray in “Lost in Translation”) and to seeing their grandchildren grow up.

Sounds great for the parents. But how about the grown-up children?

What are their secret thoughts as one, or possibly two, sets of parents move into houses a few streets away from them? It’s going to be a long-term arrangement. The Golden Years have become Golden Decades, remember.

Inevitably, though – unless merciful death intervenes – the Decades of Decrepitude will follow. Long after people become useless and helpless, they go on breathing.

So, as the kids help their Caboose Parents move in, at least some of them have to be thinking: if we accept their free babysitting now, does that mean we can’t put them in an extended care facility later?

Of course the children of my friends are nice folks who would never entertain such nasty suspicions. But I predict that the Caboose Parent trend is going to give us some mordantly hilarious TV sitcoms.