Stats Chat

Stats New Zealand crime statistics:  criminal convictions in Asian, Middle Eastern, Latin American, African ethnicity are 4.4% of all convictions in the country as a whole, 13.7% in Auckland

Population: for NZ as a whole, 10% Asian in 2006 (projected to rise to 13% in 2016).  For Auckland, 24% in 2006.

So, people of Asian ethnicity are substantially less likely to be convicted of crimes (and, presumably, to commit crimes) than the population as a whole.  Would this be so hard to check when reporting? It can’t be much harder than getting responses from political leaders, which the Fairfax papers managed.

James Curran drew my attention to this graph, from daily-infographic (original source not given, but appears to be Reddit) showing weather-related deaths in the US

The decrease in lightning deaths is impressive, but it doesn’t look as though there is much decline in tornado deaths, and apparently an increase in flood deaths.  Why isn’t forecasting helping more? Business Insider Australia also found this graph and was confused

You can pick out some major weather events — Katrina, floods, different major fatal hurricanes — from the chart, but the most interesting one is definitely lightening deaths. 

While the other systems are generally sporadic, lightning fatalities have declines. 

The explanation is simple: there are a lot more people now than in 1940 (about 2.5 times as many), so although the death rate has gone down, the number of deaths has stayed fairly stable. The National Severe Storms Lab (in Norman, Oklahoma, where they know from severe weather) gives this graph of death rates from tornados over more than a century

It would be even better to standardize by the population of the tornado-affected region, but that would be more difficult to define. It would also be better to remove some of the clutter from the graph: lose the grid lines and just have the points and a smooth curve. The message is still clear.

Deaths per million people were roughly steady until 1925, and have been decreasing since then, though the decrease may have levelled off.  The combination of sensible scaling by population, using a logarithmic scale, and adding a smoother and fitted line makes it easy to see the real trend in safety.  The first graph shows the danger of “letting the data speak for themselves”.

Two useful pieces, worth reading even if you are neither a scientist nor a science journalist.

Ed Yong writes about what he is looking for when he asks scientists for comments on a research paper.

Note that a lot of this boils down to you telling me something interesting that I couldn’t have predicted. That’s why, when people ask me, “Do you have any specific questions?” the answer is often, “No.” What you have to tell me—what springs into your head—is probably going to be far more interesting that anything I’m expecting you to tell me. Hence, any questions I have will be really broad like, “What does this mean?” or “Do you buy it?” or “How does this fit with other stuff?” or “Science me up, nerd.”

Thomas Hayden describes how he reads scientific articles as a journalist

Just after the authors note “more research is needed,” you’ll usually find the one moment of speculation allowed in most papers. That’s where scientists get to suggest not just what their study contributes to the research enterprise, but what deeper implications it might have, or even how it might be applied. This is as close as the paper will come to answering the question, “So what? Why does any of this even matter?” [Note to science reporters: your job is to push the researchers to tell you more about this. Their job is to resist.]

Team Ratings for Round 11

Here are the team ratings prior to Round 11, 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 80 matches played, 51 of which were correctly predicted, a success rate of 63.75%.

Here are the predictions for last week’s games.

Predictions for Round 11

Here are the predictions for Round 11. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

Team Ratings for Round 15

This year the predictions have been slightly changed with the help of a student, Joshua Dale. The home ground advantage now is different when both teams are from the same country to when the teams are from different countries. The basic method is described on my Department home page.

Here are the team ratings prior to Round 15, along with the ratings at the start of the season.

Performance So Far

So far there have been 88 matches played, 59 of which were correctly predicted, a success rate of 67%.

Here are the predictions for last week’s games.

Predictions for Round 15

Here are the predictions for Round 15. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

A round-up of some worthwhile links on Angelina Jolie and BRCA1

• Angelina Jolie. My Medical Choice
• Hilda Bastian (evidence-based medicine specialist and cartoonist) Keeping Health Risks in Perspective When the Dramatic and Rare Goes Culturally Viral
• Melanie Tannenbaum (social psychology) Why It Matters That Jolie Wrote About Her Medical Choice
• David Gorski (surgical oncologist and curmudgeon) Angelina Jolie, radical strategies for cancer prevention, and genetics denialism
• Gayle Sulik (medical sociologist) Angelina Jolie and the one percent
• Breast cancer screening in NZ. BRCA genetic testing is recommended and subsidized only for women with a strong family history, and where possible should start by testing one of the affected relatives to make sure that the familial pattern is actually due to BRCA1 or BRCA2 mutations, not some other gene.
• What’s actually patented in the evil gene patent.  The most important part of patent covers the short ‘mirror-image’ DNA molecules needed by the current testing technology: it will be a race to see if sequencing-based tests make the patent obsolete before it expires in 2015 (or, potentially, is overturned by the US Supreme Court later this year).

The SPCA and similar groups have put together a petition asking for a ban on testing `legal highs’ on animals. The petition shows that at least 2% of New Zealand voters support the ban, which doesn’t sound terribly impressive.  The problem is that petition-gathering is hard, so it’s not really useful unless either you get to the referendum threshold or it’s an issue that the Government wasn’t really aware had significant public feeling.  The petition opposing marriage equality (signed by nearly 2.5% of voters) had the same problem.

We’re going to get more basically uninformative numbers purporting to show public opinion from The Vote tomorrow.  Judging from the first episode and the line-up, it will be worth watching for the arguments presented, and to see whether they affect the studio audience.   The actual `vote’, on the other hand, really isn’t helpful — there’s no way that it can be interpreted even approximately as a summary of public opinion.

Even though the petition isn’t going anywhere, the issue of animal testing is worth thinking about.  The official position that a ban on animal testing is outside the scope of the bill is actually more reasonable than it sounds.  All the bill says about testing is in Section 35

35 Grounds for approving product
The Authority may approve a psychoactive product as an approved product only if the Authority is satisfied that—
(a)the application relating to the product—
     (i)complies with the requirements of section 31; and

     (ii)does not contain any materially false or misleading information; and

(b)the degree of harm that the product poses to individuals using the product is no more than a low risk of harm.

The Authority is largely on its own when it comes to policies and guidelines on how to establish the “low risk of harm”, and even on what that term means (to the extent that it isn’t implied by other law).  Presumably the government will have input, and that would be a better place to get testing standards set.

If there happens to be pre-existing data from animal tests I can’t see any real justification for excluding it, but whether new testing on animals should be required, permitted, or forbidden is more complicated.  It is absolutely necessary to test on whole mammals of some sort — I can’t imagine any regulatory committee, especially one with pharmacology and toxicology expertise, approving as ‘low risk’ a compound that had only been tested in test-tubes.  If that worked, there’d be a whole lot less failed clinical trials.  The question basically comes down to this: dogs or people?

There is actually a respectable ethical argument that testing in humans, who can volunteer, is better than testing in animals, who can’t.  Most people don’t actually behave as if they believe this argument, but some do. Even in that case, the disadvantage of testing in people is that you have to use more of them, because you aim to leave them in better condition afterwards and so have to use lower doses and cruder measurements of effect.  You might have to use, say, 20 backpackers to replace six dogs.

Personally, I think a better approach would be to decriminalize cannabis and MDMA, to cut out the market for the new smokes and party pills.  The traditional soft drugs aren’t harmless by any means, but they seem to be a whole lot less dangerous than the new substitutes.  If that option is ruled out, the proposed legal highs legislation is safer than the current policy of requiring dealers to churn through new formulations every few months, exposing people to more and more untested biologically-active chemicals. It does need some form of testing. Pick your species.

One of the first things I want to understand when there’s a natural disaster is the scale of it. Since I don’t deal with square miles or square kilometres each day, I find it hard to comprehend what an estimate of 60 square miles of damage means.

So, I used this tool to overlay 60 square miles on a map of Auckland:

Of course, the accuracy of such an estimate remains to be seen, or indeed what the level of damage is within that area, but this helps me grasp a sense of the scale of this tornado’s damage.

As part of International Clinical Trials Day, the UK National Health Service is launching “It’s ok to ask”:

Clinical research is the way in which we improve treatments in the NHS. In many cases doctors will tell patients about research but we also need patients to ask about it and keep research at the top of the NHS agenda.

In a recent consumer poll, only 21% of patients and the public said that they would feel confident asking their doctor about research opportunities – a low number.

That is why during 2013/14 The National Institute for Health Research (NIHR) is promoting the fact that it’s OK to ask about clinical research.

The campaign is aimed at patients, medical professionals and the public. Everyone can get involved and help spread the word that it’s OK to ask about clinical research.

The campaign is in the UK, but it’s ok to ask in NZ too.

The Herald says “Half of NZ workers eyeing new jobs – survey”

The photo caption even says “Of those working in property and construction, 63 per cent said they were likely to look for a new job in the next year” so they survey apparently breaks down its sample into a bunch of subcategories.

So, how reliable is this survey?  The Herald doesn’t say much about methodology, except that

The online survey canvassed 260 “professionals” working in jobs ranging from entry-level to senior management.

That’s not a lot, and you really have to wonder how they were sampled.  The Herald gets points for linking to the full glossy pamplet, but its methodology section say, in full

The Michael Page Employee Intentions Report is based  on the online survey responses of 260 professionals in New Zealand. Participants represent a range of professional occupation groups and hold positions that range from entry level through to senior management. The scope of the report includes key employee insights into preferences for attraction and retention, salary expectations, benefits and work-life balance and their views on the predicted employment outlook.

This might not be a bogus poll, but the lack of information is really not encouraging.  The report doesn’t give any demographic information that might help verify how representative it is, but it does say that 76% of those planning to change jobs intend to use recruitment consultants.

All in all, clearly a win for the flacks, not the hacks.