[*BCM*] The movement that divides us

[Adam Rosi-Kessel]

On Mon, Jun 05, 2006 at 03:53:27PM -0700, turtle wrote:
> > Another valid conclusion is that half of all bicyclists don't follow the
> > rules; and that not following the rules doesn't make you any less safe.
> Well, except that I would argue that half of cyclists don't violate the
> laws ALL of the time.  Most of the time, they are probably following
> the laws, and most of the time they don't get into crashes.

Well, yes, that's right. We'd have to know how much of the time people
are violating the laws to make any sense of Paul's statistic. I don't
think any of us know the answer to that questions.

> > Your conclusion requires the unstated premise that bicyclists who don't
> > follow the rules are a minority of bicyclists, and thus they are
> > disproportionately represented in crashes. 
> I don't see that conclusion from Paul's statement.  Why do the violators
> need to be a minority?  They can be a majority and still be
> disproportionally represented.

My unstated premise should have been that bicyclists are following the
rules most of the time... I'm also not sure that's true, or how exactly
you'd measure it.

For example, if the statistic were that 52% of heart attack victims are
women, that would tell us nothing about sex and heart attacks. (As it
turns out, most heart attack victims are men...)