Thursday, 16 August 2012

Evidence and minimum alcohol pricing

Otago's Jennie Connor and Alcohol Action NZ's Doug Sellman are angry again. This time, because Justice Minister Judith Collins cited some Masters' research done at Massey AUT showing that students surveyed said they'd not change their binge drinking habits if prices increased; they instead want the government to rely on international peer-reviewed evidence based on actual consumption patterns rather than on surveys.

And fair enough.

Fortunately, we have some evidence ready at hand. Byrnes et al, 2012, Drug and Alcohol Review. They use Australian household surveys from 2001, 2004 and 2007 to see how changes in alcohol prices affect the number of reported days of no, low, moderate, and high alcohol consumption; they find that while price increases do reduce consumption, they tend to reduce the number of days of low consumption while not changing the number of days of moderate and high alcohol consumption. This would be consistent with binge drinkers dropping the occasional beer or wine with dinner to save up for the big nights out. If policy is more worried about binge drinking than about light drinking, this might matter.

It's also mildly amusing that an Otago healthists complains about policy being based on surveys. I wonder what Connor would make of her Otago colleagues' call for banning smoking outside of bars on the basis of a survey of thirteen youths recruited in part via Facebook; the youths reported in focus groups that they'd be less likely to smoke if they couldn't smoke outside of bars. Maybe that one's ok because it's published in a journal rather than being a Masters Thesis.

Connor also notes that heavy drinkers tend to purchase cheaper alcohol relative to moderate drinkers.
“It has been established that hazardous drinkers spend less per unit of alcohol than others, and drinkers compensate for price increases by shifting to cheaper drinks. In the United States, the heaviest 10% of drinkers spend approximately $0.78 per drink compared with $4.75 per drink for the lightest 50% of drinkers.”
This only is a relevant comparison if the heaviest drinkers and lightest drinkers are drawn from the same parts of the income distribution. Suppose for sake of argument that heavier drinkers are more likely to be drawn from poorer parts of the income distribution and lighter drinkers from higher income parts of the distribution. If that's the case, we would want to compare the price paid by heavy and light drinkers correcting for any differences in income. If people with demographic characteristics similar to the heaviest 10% of drinkers but who are light drinkers spend $1 per drink (just a guess here), then minimum prices pushing above that hit both heavy drinkers and light drinkers of modest income. I know that consumption benefits from alcohol count for zero in the healthist world, but they ought to matter for policy.

At least they're not today claiming that a 10% increase in minimum prices reduce consumption by 16%...


  1. Peter, please try your comment again without the kind of language that'll get this blog blocked from high school. Thank you.

  2. From Microsoft word again, Eric’s Disqust may throw this all over the place

    About cost manipulation of alcohol and cigarettes'

    Here in Thailand I can buy a bottle of Burma whisky 40% alcohol, 750 ml, called "Hammer"
    for 160 baht, yes that's $NZ 7 for a bottle of industrial grade hooch.
    A more likely price to stay alive till the next day is $NZ 25-30, which is about the same price as a bottle of wine 10% alcohol. And yes there is a picture of a hammer on the whisky bottle, so who says Burma authority can not see the funny.

    I am an A grade alcoholic , so you can believe this letter is part of the curse on my life, because alcoholism, self inflicted is completely unacceptable to most people.
    Unknown to the average voter is that alcoholics do not have better lives if they stop drinking.

    Ask Christopher Hitchens, woops no sorry he’s dead just now.
    The fact that I drink bad whisky over here is price related.
    This is also why industrial alcoholics drink meths.
    When Governments act to price the product off the wall, many people lower consumption,
    I think. Eric seems to imply that it only takes out the minor drinkers, and as such does not do any good at all. I agree with that inferred view. But I don’t know.
    Cigarette smoking is absolutely and addiction, but when authorities raise the price, overall consumption drops. Maybe the average smoker just smokes less under pressure.
    With price control minimums, you sacrifice the few for the considered greater good.
    A good solid middle class NZ Nat party program.

  3. Prices affect consumption, sure. But my read of the evidence is that price measures have moderate drinkers reduce their consumption by more (proportionate to initial consumption) than heavy drinkers. So we then impose reasonable harm on harmless consumers in the quest to keep others from hurting themselves.