LOS ANGELES: Here’s an easy one: What do George Clooney, Johnny Depp, Reese Witherspoon, Adam Sandler, Mila Kunis, Hugh Jackman and Bradley Cooper have in common?

They’re some of the highest-paid hotshots in Hollywood, of course.

But they’re members of another group, too — paragons of Tinseltown nobility, who have headlined some of the biggest box office flops of the year. And they’re not the only A-listers who have failed to get moviegoers to theaters.

A year of high-profile bombs that kicked off with “Mortdecai” and “Jupiter Ascending” has culminated in a few more failures in the last couple weeks. “By the Sea” barely made a splash despite the star power of Angelina Jolie and Brad Pitt; “Our Brand Is Crisis” tanked, even though it starred Sandra Bullock; and this past weekend, the combined wattage of Julia Roberts, Nicole Kidman and Chiwetel Ejiofor wasn’t enough to get audiences interested in “Secret in Their Eyes.” The movie’s $6.6 million box office failed to reach even the studio’s ultra-conservative predictions. It isn’t always an actor’s fault if his or her movie doesn’t click with audiences. After all, no one is going to blame Emma Stone for “Aloha.” (That was clearly Cameron Crowe’s mess.) It usually takes a village to ruin a movie.

But the fact that 2015’s biggest debacles featured so many high-profile stars begs a question: Why do studios put so much faith in big-name actors when they clearly aren’t reliable money-makers?

Investors shy away from movies without a household name attached.

This should be a teachable moment, but most studios aren’t learning anything from the mounting evidence. They just keep looking backwards.

Not that long ago, actors were enough to sell tickets. People used to say they were heading to “the new Tom Hanks movie,” as if the star of a film trumped the subject matter. But we don’t talk in those terms anymore. No one calls “Jurassic World” “that Chris Pratt movie.”