February 26, 2014

Alcohol arithmetic not needed

From Stuff the Herald

Rising economic confidence and “aggressive” marketing techniques are the driving factors behind an 8.9 million litre rise in alcohol availability last year, says one concerned health organisation.

That sounds like a lot, but the population is also increasing. So how does the alcohol per capita change? That might take some slight effort to work out, except that Statistics New Zealand puts it in the list of Key Facts for this data release and in the media release

The volume of pure alcohol available per person aged 15 years and over was unchanged, at 9.2 litres. This equates to an average of 2.0 standard drinks per person per day.

So, probably not due entirely to rising economic confidence and aggressive marketing techniques.


Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »


  • avatar
    James Coe

    It looks to me like the link goes to the NZH, not Stuff. Spot on otherwise.

    4 years ago

  • avatar

    Snap! Your version was more polite than mine was, as usual.

    It isn’t just the per cap thing that does it though. Alcohol Healthwatch cited the total volume of alcoholic beverages available for consumption, not the total volume of pure alcohol available for consumption. Since the 2013 data had a shift from spirits to beer/wine, we basically had more water sold with alcohol in the beverage figures.

    4 years ago

    • avatar
      Thomas Lumley

      Yes, that’s why a proper calculation might have required some effort, if StatsNZ hadn’t given it as a bullet point in their press release and on their website.

      4 years ago

      • avatar

        Oh, I’m not trying to apologise for Healthwatch or the Herald.

        I just thought it was hilarious that they shouted about the increase in “total beverages containing alcohol” (despite constant per cap pure alcohol) while decrying the longer term shift toward drinks that have higher alcohol content (a shift to which decreases the total volume of beverages containing alcohol if we have constant per cap pure alcohol).

        4 years ago

        • avatar
          megan pledger

          AAC, for such a simple statistic, is really, really complicated for a number of reasons. One of those reasons is around how pure alcohol is measured.

          When StatsNZ calculate AAC, they receive details about pure alcohol volumes in pure alcohol concentration bands (mainly because it is taxed in those bands and it’s this info that gets sent to statsNZ). The tax to pay is based on a historical average of pure alcohol concentration within that band.

          With industrial alcohol that gets processed into alcopops, the pure alcohol content can be easily manipulated so it’s just below the top of the band but gets taxed at the historical average value for the band. It means that this type of drinks can give “more bang for the buck”.

          So the incentive for the producers is to put as much pure alcohol into the drink without going over a particular band.

          Over time the concentrations of pure alcohol has been increasing, as noted, but if it is mostly increasing within a band then, StatsNZ using historical average values for that band, will not show up in AAC. It means the real trend in AAC may be increasing while the reported trend is stagnant.

          Per capita alcohol consumption in Australia:
          will the real trend please step forward?
          Tanya N Chikritzhs, Steve J Allsop, A Rob Moodie and Wayne D Hall

          4 years ago