Remember kids... always wear a helmet. (The almighty bikeradar helmet thread)

Sam, the theory behind this is called 'risk compensation' and its main proponent is John Adams. Have a look at his web-site:

http://www.john-adams.co.uk/

There is also some summarised info about risk compensation on

http://www.cyclehelmets.org/.

Don't you think that the cycle helmets is a bit crazy though? In a kind of Daily Mail right wing batshit way?
I'd just have thought there was more comprehensive (or just other) info out there.