Posts from July 2012 (55)

Team Ratings for Week 20

Here are the team ratings prior to Week 20, along with the ratings at the start of the season. I have created a brief description of the method I use for predicting rugby games. Go to my Department home page to see this.

Performance So Far

So far there have been 106 matches played, 74 of which were correctly predicted, a success rate of 69.8%.

Here are the predictions for last week’s games.

Predictions for Week 20

Here are the predictions for Week 20. The prediction is my estimated points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

John Key is quoted in the Herald as not understanding minimum unit pricing

Mr Key believed that if a minimum price were set, it would change the quality of alcohol that people drank, but not the amount.

“What typically happens is people move down the quality curve and still get access to alcohol.”

The point of minimum unit pricing, as opposed to increased excise rates, is precisely to stop this.  The idea is that there is a minimum retail price for a quantity of alcohol: the proposal here was $1.50 per standard drink, in the law recently passed in Scotland it is 50p, and in the Canadian province of Saskatchewan it is $2.25.  If the price of your currently-preferred adult beverage is raised by the law, everything ‘down the quality curve’ will also have its price raised to exactly the same level.

There are reasons why it might not work: the price elasticity of demand might be low or there might be too much black-market supply. Reasonable people could also believe the benefits aren’t worth the impact on moderate drinkers: eg, at $1.50 per 12g of alcohol most red wines (at 14% alcohol) would have to cost at least $13.50 per bottle.  But, if anything, it would move people up the quality curve, not down.  That’s why it’s different from just raising excise rates.

You can read an analysis of the impact of the Saskatchewan policy, presented to the Scottish Parliament by a Canadian researcher: it seems to have reduced the quantity of alcohol drunk and also led people to drink lower-alcohol beverages.

The UK Cabinet Office (with the help of Ben Goldacre and David Torgerson) has come out in favour of finding out whether new policies actually work:

‘Test, Learn, Adapt‘ is a paper which the Behavioural Insights Team is publishing in collaboration with Ben Goldacre, author of Bad Science, and David Torgerson, Director of the University of York Trials Unit. The paper argues that Randomised Controlled Trials (RCTs), which are now widely used in medicine, international development, and internet-based businesses, should be used much more extensively in public policy.

As we have pointed out before, lots of people come up with potentially good ideas for dietary interventions, crime prevention, reductions in drug use, and improved education, to name just a few targets.     The experience from medical research is that plausible, theoretically-sound, carefully thought-out treatment ideas mostly don’t work.  In other fields we don’t know because we haven’t looked.

Each week, we would like to invite readers of Stats Chat to submit nominations for our Stat of the Week competition and be in with the chance to win an iTunes voucher.

Here’s how it works:

• Anyone may add a comment on this post to nominate their Stat of the Week candidate before midday Friday July 6 2012.
• Statistics can be bad, exemplary or fascinating.
• The statistic must be in the NZ media during the period of June 30 – July 6 2012 inclusive.
• Quote the statistic, when and where it was published and tell us why it should be our Stat of the Week.

Next Monday at midday we’ll announce the winner of this week’s Stat of the Week competition, and start a new one.
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If you’d like to comment on or debate any of this week’s Stat of the Week nominations, please do so below!