Drink, Death and Driving : Do BAC Limit Reductions Improve Road Safety?

This study exploits a natural experiment in Scotland where the legal blood alcohol content (BAC) limit was reduced from 0.8mg to 0.5mg per 100ml of blood while staying constant in all other parts of the UK. Using a difference–in–differences design, we find that this change in the BAC level had no impact on either traffic accident or fatality rates.