The whole point of this thread is that in the long run it ISN'T worth it. Go back and re-read the first post of this thread and its supporting documents.

"In all countries where helmet laws have been introduced and enforced, there has been a substantial reduction in cycle use".

The potential reduction in head injuries from helmet use does not make up for the reduction in bike usage. In other words, society would be better to ignore the helmet issue, allow a few people get hurt, but benefit from overall boosts in the health and safety of the population that would come from the increase in bicycle usage.