Even a filthy habit deserves a fair hearing

by John Kay

Financial Times
November 9, 2010

Like me, you probably disapprove of drinking and driving and dislike it when people smoke. So, like me, you may have been impressed by reports that reducing Britain’s limit on blood alcohol content for drivers would save several hundred lives a year and that the ban on smoking in public places has significantly reduced the incidence of heart attacks among non-smokers. But then I looked at the evidence for these claims.

Most analysis of the association between drinking and road accidents is based on investigation of blood alcohol levels in victims of fatal road accidents. One conclusion jumps out from these data. Most people who have been drinking and are killed on the road are not close to the limit. They are drunk. Two-thirds of victims of fatal road accidents who were over the legal limit had blood alcohol levels more than twice the legal limit. Many of them had consumed much more.

The claim that reducing the legal limit would save many lives is entirely based on the belief that such a measure would have a big effect on the behaviour of people who are already well above the legal limit. The principal evidence for this claim is a study undertaken in South Australia. But the incidence of drunk driving in South Australia was then 10 times the current figure in the UK. Australia used to have a culture of the drive-in bottle shop, which would fill your car boot with cans of beer. A raft of policies have sensibly addressed the issue. The social context is so different that Australian experience is almost irrelevant.

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