Stats Chat

A graph originally from JP Morgan, and now around the web (via, and via) comparing the social, economic, and political heterogeneity of the Euro zone to various hypothetical monetary unions, some more plausible than others.  The Eurozone is more heterogenous than all of them.

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 June 8 2012.
• Statistics can be bad, exemplary or fascinating.
• The statistic must be in the NZ media during the period of June 2-8 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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Q:  Have you seen the  new story in Stuff about chocolate being good for your heart?

A: Indeed.  A fine example of the genre.

Q:  What did the researchers find out about the benefits of chocolate this time?

A: Absolutely nothing. (Here’s the research paper)

Q: Then what is the story about?

A: They assumed that there were significant cardiovascular benefits of high-cacao dark chocolate, based on short-term studies of blood pressure and cholesterol, and worked out what the population impact of chocolate therapy would be if that was true.

Q: And is it true?

A: That’s not clear.  If you remember the last time we encountered ‘chocolate for health’, the benefits in that study were pretty marginal. This time the researchers cite a pooled set of studies giving a somewhat larger estimate of the benefits.   Also, the research showing benefits on blood pressure and cholesterol has been from very short-term studies, and extrapolating to the longer-term may well be unreliable.  Still, as Prof Reid points out, no-one is going to do any reliable studies, so extrapolation is what we’ve  got.

Q: What about the calories and fat?

A: Well, the studies that provided the estimates of benefit compared chocolate or cocoa powder to a control that supplied the same calories and fat, so we don’t know.   The researchers (and even the newspaper) admit “The study did not take into account weight gain … ”but that is something you would need to consider,” [Prof Chris Reid]  said.”

Q: Ok, if we stipulate all of that, how big were the benefits?

A: Moderate:  treating 10,000 high-risk people with chocolate would, under the most favorable assumptions, prevent about 15 fatal and 70 non-fatal heart attacks and strokes over a ten-year period.

Q: How do the benefits compare to pills?

A: Well, thiazide diuretics provide 2-3 times the blood pressure effect, and simvastatin provides maybe 10 times the cholesterol reduction. And they cost Pharmac less per month than the chocolate would cost you per day. And we really know the reductions in risk factors translate to fewer heart attacks, strokes, and deaths

Q: But didn’t the researchers say that chocolate therapy would be cost-effective?

A: They said it would be cost-effective at a cost of $42/year.   According to their website, if you wander down to your local Countdown, you can currently get Whitaker’s Dark Ghana at $3.79 for 250g. That would be $550/year for the 100g/day dose in the paper. And that’s a sale price.  It’s only cost-effective if you don’t count the cost of the chocolate.

Q: How about cocoa powder?

A: One of the studies that went into the analysis used 31g/day of cocoa powder (`natural’ not Dutch process). That’s cheaper, but it’s still a lot more than $42/year, and 5 tablespoons/day is a lot of unsweetened cocoa powder.

Q: So, should I eat dark chocolate?

A: If you like it, sure.  If you’re just choking it down for the cardiovascular benefits, probably not.

Yesterday’s episode of The Nation had an interesting piece on the work that Statistics New Zealand does, its history and relevance to all New Zealanders:

Watch the video here »

Statistics New Zealand is also a finalist in the upcoming public sector excellence awards in three categories.

An interesting report in the Herald yesterday on methamphetamine use.   A forthcoming Health Ministry survey apparently shows a decrease in the proportion who report using P over the past year, from 2.1% in 2007/2008 to 1% now (yes, that will be larger than the margin of error; it’s a big survey).

On the other hand, an ongoing Massey University study that interviews police detainees about drug and alcohol use finds that the street price and availability of P have not really changed.

This evidence of a decrease on the demand side is encouraging for two reasons.  First, it suggests a decrease in the number of people who are dumb enough to want to take methamphetamine, which has to be progress.  Second, it suggests that the pseudoephedrine ban wasn’t responsible, as that should have acted on the supply side by driving up street prices.  Can we have our Sudafed back?

Team Ratings for Round 13

Here are the team ratings prior to Round 13, 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 91 matches played, 53 of which were correctly predicted, a success rate of 58.24%.

Here are the predictions for last week’s games.

Predictions for Round 13

Here are the predictions for Round 13

Team Ratings for Week 15

Here are the team ratings prior to Week 15, 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 94 matches played, 66 of which were correctly predicted, a success rate of 70.2%.

Here are the predictions for last week’s games.

Predictions for Week 15

Here are the predictions for Week 15. 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.

The Herald has a story about curcumin, a component of turmeric (which, as you know, is what makes curry stains hard to get rid of).  Apparently it also has some interesting effects on  a component of the immune system. The story appears in quite a few newspapers around the world, and in Science Daily and Medical Daily, which collect this sort of story.

Often it’s hard to tell how much the stories depend just on the press release or whether someone at one of the specialised sites has actually taken a look at the paper.  It’s not hard in this example, though: the paper hasn’t appeared yet.  There seems to be some slipup at the journal. The university press release and all the sites say the paper came out Friday 25th May, but the Journal of Nutritional Biochemistry hasn’t gotten to Friday yet: at the time of writing this they are still on Thursday 24 May.

The Herald had a  clicky poll on the proposed R-plate restricted-driving legislation, and has reported the results in an unobjectionable paragraph at the end of a good story getting input from experts.  I’m not sure that the poll actually adds to the story, but at least it doesn’t subtract from it.

You can report a self-selected sample responsibly: the Otago Daily Times shows how. Their lead:

Ninety percent of people who have made submissions on the Queenstown Lakes District Council representation review want to keep an Arrowtown ward and councillor.