Regulating responsibility never works the way we would like. Todo brings up a good example of the problems that can happen. But the real question is do we leave the responsibility up to the adult individual or the minors parents or do we legislate/mandate use?
For adults my answer is simple, no legislation or mandates. To the contrary, the legislation should be that for adults not using helmets they should bear the burden of proof to establish that any injury they sustain in an accident would not have been prevented or mitigated by helmet use. If they cannot prove this fact, they would have no cause of action, and would not qualify for public assistance in medical or rehabilitation of the injury. In essence, I think we should place the full responsibility of helmet use and the consequences on the adult individual.
As for kids, however, the issues are more complicated. If a preponderance of the empirical evidence shows that helmets are substantially more beneficial than detrimental, legislating mandatory use is reasonable, but it infringes on the parents role as parent. Most states have taken this step with respect to car seats and bike helmets because the evidence is clear that helmets reduce injuries but there are a significant number of parents who are either irresponsible or who seem to be more swayed by economic considerations than they are by the well being of their children.
The CPSC is requesting skiers use helmets. The following data is revealing http://www.bhsi.org/skicrash.htm
Further, the better studies I have reviewed show that the risk of injury for children is relatively high at nearly one quarter of all injuries in this group being head injuries http://hsc.virginia.edu/medicine/cli...b/skihelm.html
I support legislation/mandatory helmet laws for children under the age of majority. I do not support legislation/mandatory helmet laws for adults; instead I support liability limiting measures and the like.