Originally Posted by
wphamilton
Don't lose sight of what we're measuring and why. When we are talking about helmet advocacy, helmet laws, costs and safety in context of the interest of the State or society, then absolutely it should be based on every single rider.
No, it shouldn't be based on every single rider because not all riders are the same.
Anyway, people are concerned about helmets discouraging riding yet they are OK with using a possibly-bogus average risk number doing the same thing!
Originally Posted by
wphamilton
I've said time and time again that my own risks would be different - no matter how many times you say that as if I'm arguing otherwise. It makes no difference to the risk measurement.
If your risks are known to be different (mostly related to taking action to increase or reduce the likely risk), the average risk
doesn't apply to you.
The average is a
poor predictor of indivdual risk (given the wide variation that would seem to be reasonable to expect). If the individual is a member of a subpopulation that is significantly different, then the average of the entire population is a even worse predictor.
This is basic statistics (though it's something that many people don't get).
(The average is an OK predictor of
pooled risk, which is what insurance companies are interested in.)
We don't really have any indication that the "3-5 fold" risk is even accurate. (It might not be that difficult to produce rather different "averages" with small changes in assumptions or what is being measured.)
It's also misleading to quote a single number rather than a range because it suggests that the magic number is more accurate than it ever could be.
Originally Posted by
wphamilton
The range is 3-5 times. Three times, or even five times, the risk of driving (per mile or per hour) is probably low in my particular case.
If you really believed that, it seems odd that you would still keep riding.