Tuesday, 29 July 2014

Peltzman at the Ring?

The International Boxing Association last year banned the use of headgear by amateur boxers starting on the first of June, 2013. I'd missed it then but caught it via @SirWB. Why'd they do it? Peltzman effects, or at least perhaps:
Amateur boxers are to be banned from wearing headgear in a bid to reduce the number of head injuries.
While the move sounds counterintuitive, the theory is that opponents don't apply so much force if the head is unprotected.  
The new rules, from the International Boxing Association (AIBA), state that from June 1st, amateur, elite male boxers who compete internationally will be banned from wearing headgear, like their professional counterparts. Another reason for the move is that headgear can obscure peripheral vision, making it harder to see when a blow is being aimed at the side of the head. Indeed, research has shown that a lack of headgear actually reduces the risk of concussion.

While drivers take more risks around helmeted cyclists, drivers aren't really trying to knock out cyclists. If you're minimising expected harm to others subject to your own cost constraints, optimum abatement goes down with the other party's mitigating efforts because expected harm drops.

But I can imagine scenarios where optimal punch force either increases or decreases in the presence of helmets. If you need to apply more force to get any effect in the presence of helmets, then optimal force would be lower without helmets if exerting force is costly in terms of exhaustion. But it's also pretty plausible that it's much harder to knock out a helmeted opponent than an unhelmeted one; if a connected hit at maximal force is sufficiently unlikely to knock out a helmeted opponent relative to an unhelmeted one, then there could be a substantive change to the returns to strenuous force. Whether optimal punch force goes up or down then isn't obvious to me (though it likely would be to somebody who has boxed).

A Peltzman story on the defence side would require that helmeted boxers take less care to avoid hits to the padded areas than to the unpadded chin, and that cumulative hits to the padded parts cause longer-term damage. And, that isn't inconsistent with some of the commentary from trainers at the time of the ban:
  • “I’m not for it at all. I like the protective gear. Without it, everyone’s going to have to be much more vigilant, that’s for sure.” — Dr. Sonny Arkangel, S.A. ringside physician
  • “It’s going to change the way we train kids now. There was a comfort zone with headgear. Without it, your defense is going to have to be better.” — Joe Rodriguez, local trainer
A year's gone by, so that should be plenty of time for a diff-in-diff study: headgear continued to be worn for women, senior and youth divisions; it was only banned for elite males during advancing tournaments, according to the story above-linked. But whether any reduction in concussions were due to Peltzman effects or due to better defensive peripheral vision in the absence of helmets ... I can't see how that could be disentangled. Well, if they brought back blindfold boxing and and checked the magnitude of helmet effects there as compared to ... no that wouldn't work either as helmets could arguably also muffle sound.

Update: the Economics Department's pugilist, Steve Agnew, reports (via Paul Walker):
The second explanation from the trainers about boxers blocking with their headgear is right. The not wanting to hurt your opponent explanation is bollocks, as is the chance of knockout v strenuous punching argument.
 The biggest pain in the arse with headgear is the heat. The headgear prevents a reasonable amount of your body’s heat escaping through your head. It is much more tiring to fight with headgear than without. That’s why in most gyms, fighters don’t spar with headgear.The biggest pain in the arse with headgear is the heat. The headgear prevents a reasonable amount of your body’s heat escaping through your head. It is much more tiring to fight with headgear than without. That’s why in most gyms, fighters don’t spar with headgear.