On le Twitter, EE pal Adam Gurri asks: "@Spivonomist the concussions in football thing seems like a clearcut case of people being uncomfortable with the BATNAs."
I reply: "@adamgurri BATNA for whom? Players or the audience? Ooh, what are the likely BATNAS? Get ride of helmets and what do we have?"
To which he writeth: "@Spivonomist Players. Argument that "they're choosing to do this, they make serious $$$" not euvoluntary."
There are a few considerations here. The easiest is a cross-sectional game theoretical question. What would happen if the NFL got rid of helmets and pads overnight? The strict game theoretical SPNE is that players would stop making big hits and we'd see something closer to rugby, Aussie-rules footie, or bare-knuckle boxing: more blood, fewer deep-tissue blunt trauma cases. But we know empirically from other rules changes that SPNE predictions under radical rule changes disrupt play heuristics and we'd probably see a lot of chaos for a season or two until players and coaches adjust to the new norms. In the meantime, there would be a lot of broken bones and spinal column damage. That's not all that fun for the fans, I think.
But I don't think that's what Adam's worried about. He's too sophisticated a thinker to bother with something so trivial. No, the real problem is that NFL participation is a rent contest embedded in a human capital development tale, governed by the fickle tickle of Lady Luck. The BATNA for an established NFL player (even a median-earnings player) is unlikely to draw all that much sympathy from the crowd. Yeah sure, there would be some (unpleasant) adjustment costs to reducing football concussions and revenues might suffer for a couple of years, but it does seem worth it, all things considered. But when you think about the problem longitudinally, we're no longer talking about paid professionals, we're talking about little kids in Pop Warner leagues who have to do their arithmetic homework after practice. That generates a whole different set of moral intuitions.
For a pro player, all those years spent doing drills and learning plays are sunk costs. For the kid, they're opportunity costs. And we have a decent inkling from the behavioral literature that people are pretty bad at judging risk and uncertainty, or maintaining reasonable discount rates. Kids even less so. It's far from clear that the very real risk of concussion enters correctly into the decision calculus of whether or not to seriously pursue a sports career.
So I encourage you to pay close attention to how folks sell the idea of rules changes. BATNA estimates look very different depending on which side of the decision node you're sitting. You can expect folks who want to make football more concussion-free to argue ad puerum and the status quo crowd to stress the (rather disastrous) short-term consequences.
Which side is right? Take a good long look at your kids tonight and you tell me.