[raphman_]

A few years ago there was a discussion about making bike helmets mandatory in Germany. At least one scientist [1] did a cost-benefit analysis and argued against such a law. For example, while fewer people would die of head injuries, many more people would stop riding bikes (or do it less often), leading to an increase in cardiovascular diseases.

[1] http://www.cycle-helmets.com/germany-helmet-law-cost-analysi...