George writes:

I don't know why you are ridiculing that helmet study. You wouldn't let your kid ride a bike without a helmet. The law helps other parents who have no safety sense or are not good at controlling their kids.

Yes, I do let my kid bicycle and roller skate without a helmet. It is the medical journals that have no safety sense. This article had no evidence about safety. Most of the helmet research is very seriously flawed. I do not want nanny state laws to substitute for routine parental decisions.

Jeff also objects to my comments about the helmet study, and writes:

What is "unscientific" about an observational study? Does it make conclusions that cannot be tested?

Yes, it makes untestable conclusions. The conclusion is that someone should intervene with these kids. It says, "public education and interventions should target children and their parents as well as scooter riders." That cannot be tested -- it is just someone's opinion about how kids should play. It is like a conclusion that says, "The kids could get hurt playing outside. They should just stay home."

JG writes: I think you might have it backwards; I rather imagine the "unobtrusive" observers formed their "conclusions" first and then went out to gather data that would, in *their* minds, support them.

You're right. Can you imagine a medical study that said this?

We visited a kids' playground, and found all the kids playing and having fun in a safe manner. In fact, we found that undue attention to safety was paid. The swings and monkey bars were torn down because they were erroneously thought to be dangerous. A kid was not allowed to ride his roller skates because his mom forgot his elbow pads. The baseball field was replaced with a soccer field. When storm clouds formed, all the kids had to go home because of a paranoid fear of lightning. A security guard was hired because of suspicious unrelated adults who were loitering with clipboards, even tho they were doing legitimate medical research. The city would have saved money and the kids would have had more fun and everyone would have been just as safe if there had been less concern about safety.

It just wouldn't happen. The kind of people who do these studies are not interested in who is having fun, or saving money, or rationally ignoring a minor risk. If they have to control people to get some alleged medical benefit, so much the better.