Friday, October 20, 2006

Should seatbelts be compulsory?

Assume they should be. Other things being equal, it's safer to crash while buckled up and many people wouldn't wear a seatbelt if they didn't have to, so an enforced seatbelt law should reduce the number of road deaths right? Not necessarily, people may choose to drive faster or more recklessly instead. So other things are not equal; people change their behavior. When America made seatbelts compulsory motorists had more accidents, killed more pedestrians but got killed at about the same rate.

Does this affect your opinion about seat belt laws? One response is that the law is fine, but people should drive as carefully as they did before (or more carefully!); then there would be fewer deaths. That's true, but if scolding motorists into new attitudes is a viable strategy, why do you need the seatbelt law in the first place? Surely you can just scold drivers into buckling up? When making new laws you can't simply will people to change their behavior in ways you find desirable.

Should seat belts still be compulsory?


Mandy said...

Hmmmmm but what if you are brought up having it drummed into you that wearing seatbelts is the norm - then you will not measure how safely you drive against not wearing setabelts at all - but rather other things and the 'saftety bar' will get higher and higher and driving safer and safer - surely?

stuart said...

i agree that different cultures can have different attitudes to risk but I don?t know how much the seatbelt part plays. Risk averse people will wear the seat belt anyway, the law only affects those who don?t want to wear it. The fact is that there are trade offs. Those who don?t wanna wear the seatbelts can compensate in other ways. The benefit they get, is more time on the phone, less time in the car, whatever, but it?s up to the driver.

A better way of saving people is changing their attitude to risk, how would you do this? Would you want to?

But the way. I would oppose seat belt laws even if they did save lives.

cristi said...

people might drive faster with seatbelts, but i don't think the risk is equal to the speed people drive without seatbelts. You don't have to drive fast at all to kill yourself without a seltbelt. I tried this machine at killary race track, which allows you to feel the inertia of a car stopping at a low speed (I think it was 20km/hr. If i wasn't belted up, i would have gone flying. I can easily see how 40km/hr would kill me.

I don't think the research is entirely sound about the increase speed after seltbelt laws. You must remember that the law came about because the cars being built at the time were suddenly much faster than previous cars. death rates would have only just recently increased before the law came about. people would have driven faster after the law becasue their cars allowed them to.

stuart said...

Cristi! I'm appalled! How can you judge the soundness of research based on your own intuitions? 10 minutes ago you were railing against mere opinions.

You overemphasize speed; there are plenty of ways to be reckless. I don't know if it's true that cars suddenly became faster at that time, but I am sure it would have been controlled for.

I haven't read the research on the topic, but here's a nice article.

cristi said...

HA! you just used your own intuitions too.

"i'm sure it would have been controlled for"

I am pretty certain that cars did suddenly get alot faster, but before i put money on it, i'll ask my dad. seriously, when it comes to cars, my dad is a more reliable resource than dare i say The Economist!

I based my bias of the research by the language you used. "killed at about the same rate" is what raised flags for me. i'll read the article tho, maybe i'll change my mind

cristi said...

hmmmm, as predicted, article is suspicious.

firstly, he is a cyclist. no further comment needed there.

finally, even when we drive carefull when seatbelt doesnt work, as writer suggests, i'll garantee that we are still driving at speeds that will kill us without seatbelts. there may be other forms of recklessness, but speed is the biggie.

stuart said...

well, since neither of us seems to have any intention of reading of reading the paper we need to rely on armchair speculation. i guess i just find my assumption more plausible. the paper appeared 31 years ago is well known amoung economists and there is apparently no knock down refutation, no economist has thought of the speed thing?

also in my limited knowledge of economics, controlling for these things is very important to what they do. to miss the most obvious thing to control for, and everybody else as well???

yes cars have gotten faster, which means more deaths (starting from 0 100 years ago when they couldnt go faster than you could jog), but i'll need to see some pretty startling stats before i veer from my armchair position.