This helmet promotion decreases ridership, in terms of public costs (money) this is good. If you are not willing to ride a bike because you won't wear a helmet, then you won't get in an accident and hurt your head. The choice to ride a bike without a helmet can have severe costs (money) either the government has to pay for their healthcare or members of the same insurance program do. If you don't wear a helmet and you get in an brain altering accident, someone has to pay for your medical care (maybe even your family). It's that simple. Yeah, I want people to ride bikes too, but we should do it responsibly. I used to ride without a helmet and I never hurt my head, but a lecturer in my program went on one time to ride his bike without a helmet, he got into a very severe accident, has a good amount of cognitive deficiencies, and struggles everyday with his decision (he almost died and was in a coma for a good month). But in addition to his personal costs, he cost his healthcare provider. Your brain is who you are, if you mess it up you'll never be the same person that you are now. If that is the risk you are willing to take then so be it. And this is probably not a risk for people who ride 10mph and slower, but if you ever get those pedals spinning and get your bike in the near 30s, then one tire puncture, on chain slip, could send you headfirst to a new personality. But then again it may not, the data presented at the beginning of this article are scientifically meaningless. Hell they even make cool hipster helmets now. Put an argyle sticker on it and enjoy. If you do a job where you use your brain not your body (even bike mechanics) then you lose your brain, you've lost your ability to make money.