Stats Chat

• The Herald says House prices: ‘Another bloodbath’ as prices slump again in May for sixth straight month – REINZ figures. Estimates in the story range from 10-15% drop by the end of the year, and maybe 18% peak to trough.  In January, the Herald reported that prices had risen 30% in 2021, so even an 18% drop would leave prices about 10% higher than they were at the start of 2021.  So even the most optimistic forecast has housing prices pretty much keeping up with inflation over 2021-22.
• Emma Vitz updated her housing price maps for the Spinoff, which you probably saw this time last year
• Len Cook, former Government Statistician of New Zealand and former Chief Statistician of the UK, is Not Happy with the proposed  Data and Statistics Bill,  replacing the old Statistics Act.  As I said on Twitter, you don’t necessarily have to agree with Len, but you do need to pay attention to what he thinks.
• Covid has now killed more White people in the US than Hispanic or Black or Asian, according to a New York Times story.  As this Twitter thread points out, that’s because of age differences in the populations of different ethnicities.  Mortality rates are lower for White people <45 than Black or Hispanic. The same is true for White people 45-64. And 65-74, and over 75. Because the White population averages older, the total numbers of deaths are higher — but that’s like the way deaths are higher in Australia than New Zealand because the population is larger.  Age standardisation is really important if you want to think about reasons for differences between groups

Team Ratings for Round 15

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 108 matches played, 76 of which were correctly predicted, a success rate of 70.4%.
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.

Team Ratings for the Final

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 150 matches played, 109 of which were correctly predicted, a success rate of 72.7%.
Here are the predictions for last week’s games.

Predictions for the Final

Here are the predictions for the Final. 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 the Semi-finals

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 183 matches played, 133 of which were correctly predicted, a success rate of 72.7%.
Here are the predictions for last week’s games.

Predictions for the Semi-finals

Here are the predictions for the Semi-finals. 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 the Super Rugby Final

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 90 matches played, 67 of which were correctly predicted, a success rate of 74.4%.
Here are the predictions for last week’s games.

Predictions for the Super Rugby Final

Here are the predictions for the Super Rugby Final. 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 the Final

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 155 matches played, 90 of which were correctly predicted, a success rate of 58.1%.
Here are the predictions for last week’s games.

Predictions for the Final

Here are the predictions for the Final. 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 the Semi Finals

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 41 matches played, 28 of which were correctly predicted, a success rate of 68.3%.
Here are the predictions for last week’s games.

Predictions for the Semi Finals

Here are the predictions for the Semi Finals. 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.

• The “Causality, Applications, and Research in Education and Statistics” lab at Harvard has a blog. A bit more technical than StatsChat.
• There are many contexts where absolute risk differences are more relevant than relative risks, but as Hilda Bastian explains, not all.
• Making data ‘visual’isation more accessible for blind and low vision users.
• Good graphics-based electoral data analysis from the West Island
• “In search of the least viewed article on Wikipedia” and why it’s about a moth
• Representing images from the Hubble telescope with sound?
• Science education in an age of misinformation
• The average gun in the US has a relatively low chance of killing someone, but the average person has a relatively high chance of being killed. Which is the most useful denominator?
• Science editing handbook from the Knight School of Journalism at MIT

From the Herald today (from the Daily Telegraph)

The story is somewhat better than the headline — for a start, it mentions in the second sentence that this is unpublished research being presented at a conference, so it’s really just a press release and there won’t be much further information available.  There’s a slightly more detailed story at Yahoo, from the Evening Standard.

You might think from the the headline that the research studied men who ran marathons after the age of 40, and that it came with recommendations not to do this.  Not quite. These were people aged over 40 who had taken part in more than 10 endurance events and had exercised regularly for at least 10 years, but quite a lot of their excessive exercise could have taken place when they were under 40.  More importantly, there wasn’t a “warning”:  the Yahoo piece quotes the researchers as saying

“In non-athletes, aortic stiffening is associated with heart and circulatory diseases.

“How this finding applies to potential risk in athletes is not yet fully understood, so more work will be needed to help identify who could be more at risk.”

As usual, this isn’t the first piece of research on the topic.

Earlier research of endurance athletes over 50, from 2020 (press release, paper) supports the current findings. It did find enlargement of the aorta in male but not female athletes, and like the current research it came with vague concerns rather than dire warnings

The first option is that aortic enlargement among masters athletes is a benign adaptation and another feature of the so-called athlete’s heart, where big is good. “The alternative is that being a lifelong exerciser may cause dilation of the aorta with the sort of attendant risk seen in nonathletes.”

A 2021 paper looked at the ‘aortic age’ in people doing their first marathon, at ages ranging from 21 to 69. It found

… a reduction in “aortic age” by 3.9 years (95% CI: 1.1 to 7.6 years) and 4.0 years (95% CI: 1.7 to 8.0 years) (Ao-P and Ao-D, respectively). Benefit was greater in older, male participants with slower running times (p < 0.05 for all).

That is, if these measurements have the same interpretation in athletes as in normal people, running a single marathon seems to be good for men over 40.

It might turn out that overindulgence in marathon running is bad for your cardiovascular system, but we’re not there yet.  If you’re running for fitness, you might be better off not going the full 42km. But if you enjoy it, go in (hopefully) good health.

Team Ratings for Round 14

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Performance So Far

So far there have been 100 matches played, 69 of which were correctly predicted, a success rate of 69%.
Here are the predictions for last week’s games.

Predictions for Round 14

Here are the predictions for Round 14. 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.