Transformers: Age of Extinction is now the highest-grossing film released in China after a matter of weeks. Comedy doesn't travel as well.
But before we get too annoyed with those giant-robot-loving Chinese, perhaps we should consider another reason 21st-century Hollywood comedies aren't pulling in the big bucks. Could it be, simply, that they aren't very good? Some are awful (e.g. almost every Adam Sandler film), but most are aggressively, defiantly okay-ish.
Should you ever slump in front of We're The Millers or Wanderlust or Bad Neighbours, you probably won't hate it. You'll probably smile a few times. But will you float away afterwards, buoyed by the knowledge that the film could scarcely have been any more hilarious? Don't make me laugh.
I blame Paul Rudd and Seth Rogen. In 2005, a TV writer-director named Judd Apatow made his film debut with The 40 Year Old Virgin. It included an improvised sequence in which Rudd and Rogen sit side by side, playing a video game and trading jokey insults, each one introduced with the question, "You know how I know that you're gay?"
What's striking about the scene is that it's barely a scene at all. Plot-wise, you could cut it without affecting the rest of the film one jot. But it does help foster the illusion that Apatow's characters are old buddies having a laid-back, unscripted conversation - and in 2005 that was thrilling.
At the time, the Hollywood comedy landscape was dominated by the romcom at its most insufferable. The likes of The Wedding Planner and How to Lose a Guy in 10 Days were essentially advertisements for haute couture and luxury apartments.
The 40 Year Old Virgin and Apatow's follow-up, Knocked Up, were a different matter.
Shifting the genre in a more testosterone-heavy direction, Apatow's comedies had unshaven, dope-smoking, gym-phobic slobs having the sort of affable, expletive-peppered chats the average man might have if he was as funny as they were. It was jazzy, breezy, radical stuff.
The dress-montage romcoms continued - and many starred Katherine Heigl, the leading lady in Knocked Up - but their days were numbered. The success of The Hangover in 2009 sounded their death knell. It wasn't directed by Apatow, but like his films, it had no A-list stars, a rambling story about a gang of socially irresponsible men and an R-rating. It was also the 10th-highest grossing film of the year. After that, there was no going back.
Subsequent comedies no longer needed to be tightly scripted, family-friendly vehicles. They could have loose-at-the-seams plotting, a what-the-hell indie attitude, and acres of improvised, scatological banter - and they could still make a fortune.
No wonder every recent high-profile comedy appears to have been directed, produced or at least influenced by Apatow and to have featured actors from his unofficial repertory company - Rogen, Rudd, Jason Segel, Jonah Hill, James Franco, et al.
Unfortunately, this new style of comedy has come to seem as smug and artificial as the old. Screenplays have become baggier and ever more reliant on improvisation, even as that improvisation becomes ever more limited - if you took away the swearing and the pop-culture allusions, there wouldn't be much left.
The problem is that Apatow's easy-peasy, make-it-up-as-you-go-along approach is ideal for comedies about stoners and slackers slouching towards adulthood, but less than ideal in other contexts. And it's fatal for films with a premise involving jeopardy and urgency - see such action-comedies as Your Highness, The Green Hornet and Land of the Lost.
In these, the ramshackle, haphazard plotting kills the momentum, while the extemporised babbling continually reminds you that you're not watching innocent people in danger, you're watching comfortable comedians throwing out wisecracks.
By 2012, when Apatow directed his wife and daughters in a 134-minute home movie, This Is 40, his techniques had become synonymous with self-indulgence. They were also ubiquitous. I can still remember hearing the whip-cracking screwball dialogue in Silver Linings Playbook, also in 2012, and realising, to my excitement, that it wasn't improvised. It's the kind of excitement that today's US comedies rarely offer.
That's not quite true. American sitcoms have never been stronger: watch an episode of Parks & Recreation or Modern Family, and you'll know a team of writers has fine-tuned the script. And, because of the 20-minute duration of US network sitcoms, only the best moments of improvisation reach the final cut.
And then there are cartoons. Top-tier digital animation is so expensive and time-consuming that every second has to count, so there's no room for sloppiness. Look at the work of Phil Lord and Christopher Miller, two directors who switch between live-action and animated films. Their flesh-and-blood comedies, 21 Jump Street and 22 Jump Street, are funny in their shapeless, shambling way.
But their cartoons, Cloudy with a Chance of Meatballs and The Lego Movie, are far, far better. Why? Because when you're employing several dozen animators, you can't rely on Jonah Hill riffing about his genitals for a cheap laugh.
But the difference isn't just down to production methods. It's also down to the target demographic.
While cartoons and sitcoms are angling for viewers of all ages, big-screen live-action comedy is now content to wink knowingly at youngish, media-savvy males with a penchant for jokes about sex and drugs. And ultimately, it could be that Hollywood comedies are playing to smaller audiences because they're aimed at smaller audiences.
If they abandoned the Apatow approach in favour of propulsive storylines and well-structured comic setpieces, maybe those Asian viewers would be keener. The rest of us might be keener, too.
