Friday, 9 September 2011

Another Alcohol Con

If you haven't already bookmarked the excellent Straight Statistics, you really should. Their latest article is a routine debunking of some routine junk science from Alcohol Con(cern) who came up with the amazing finding that alcohol sales correlate with alcohol consumption. Or, to be precise, that alcohol-related hospital admissions are correlated with the number of off-licenses in an area.

But not in London. So they left that out.

This is such a blatant conflation of correlation and causation that even Ben Goldacre—who never criticises 'public health' bad science and sometimes defends it—emerged to poke fun at it.

A red-faced Don Shenker knew exactly what he was talking about and replied...

To which Goldacre rightly responded...

As Straight Statistics points out, Alcohol Concern quite explicitly did claim causality:

Under the heading Methodological Qualifications, the new report states: “This study did not set out to establish cause and effect.” Yet the previous page asserts that nearly 10 per cent of all alcohol specific hospital admissions in England, excluding London, are directly attributable to off-licence density, “meaning availability rather than any other external factor is the cause of one in ten of such harms”.

So either Don Shenker doesn't understand that if you say something is "the cause" you are claiming causality or he is a liar. I make no judgement on that but urge you go read the rest.


Anonymous said...

Just in case anyones thinking of donating to Comic Relief, note that they donated money to Alcohol Concern. So, child poverty been seen off now. Glad to hear it.

Curmudgeon said...

Not only are AC mistaking correlation for causation, in this case they have cause and effect the wrong way round. Demand for off-trade alcohol (which overall probably has a fair correlation with levels of underage drinking) affects the number of off-licences, not the other way round.

Anonymous said...

The report got a kicking on R4's More or Less last week. They pointed out that off-licences tend to open in areas where people like a drink.