Originally Posted by
CrimsonEclipse
That's the answer.
If you're not sure of an answer due to political, cultural, or personal pride, check to see what insurance companies think.
They tend to brush off society norms in the name of capitalism.
Translation: Follow the money.
Exactly. They depend on their actuarial tables to establish policies and rates. Their numbers have told them that the use of bike helmets saves them money.
More cynically, they can contest or deny a claim resulting from injury or death of a cyclist by citing the absence of a helmet, but that would still be argued on the basis of their data showing that bike helmets generally reduce accident trauma.