Posts filed under General (3156)

October 16, 2014

Do you feel lucky?

I’m glad to say it’s been quite a while since we’ve had this sort of rubbish from the NZ papers, but it’s still  going across the Tasman (the  Sydney Morning Herald)

If you’re considering buying a lottery ticket, you’d better make sure it’s from either Gladesville or Cabramatta, which are now officially Sydney’s luckiest suburbs when it comes to winning big. 

NSW Lotteries has released statistics that show the luckiest suburbs across all lotto games in NSW and the ACT, as well as other tips for amateurs hoping to ring their bosses tomorrow morning to say they wouldn’t be coming in to work. 

Of course, the ‘luckiest’ suburbs are nothing of the sort: just the ones where the most money is lost on the lotteries. Cabramatta has improved a lot in recent years, but it’s still not the sort of place you’d expect to see called ‘lucky’.

October 15, 2014

Currie Cup Predictions for the Semi-Finals

Team Ratings for the SemiFinals

The basic method is described on my Department home page. I have made some changes to the methodology this year, including shrinking the ratings between seasons.

Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Current Rating Rating at Season Start Difference
Lions 6.03 0.07 6.00
Western Province 6.02 3.43 2.60
Sharks 4.36 5.09 -0.70
Blue Bulls 1.02 -0.74 1.80
Cheetahs -3.53 0.33 -3.90
Pumas -8.20 -10.00 1.80
Griquas -10.10 -7.49 -2.60
Kings -14.91 -10.00 -4.90

 

Performance So Far

So far there have been 40 matches played, 29 of which were correctly predicted, a success rate of 72.5%.

Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Kings vs. Pumas Oct 10 26 – 25 -2.20 FALSE
2 Lions vs. Cheetahs Oct 11 47 – 7 11.30 TRUE
3 Western Province vs. Sharks Oct 11 20 – 28 8.70 FALSE
4 Blue Bulls vs. Griquas Oct 11 46 – 12 13.70 TRUE

 

Predictions for the SemiFinals

Here are the predictions for the SemiFinals. 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


Game Date Winner Prediction
1 Lions vs. Sharks Oct 18 Lions 6.70
2 Western Province vs. Blue Bulls Oct 18 Western Province 10.00

 

ITM Cup Predictions for the ITM Cup Finals

Team Ratings for the ITM Cup Finals

Here are the team ratings prior to the ITM Cup Finals, 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.

Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Current Rating Rating at Season Start Difference
Canterbury 13.65 18.09 -4.40
Tasman 10.97 5.78 5.20
Counties Manukau 6.58 2.40 4.20
Auckland 6.05 4.92 1.10
Taranaki 5.06 -3.89 9.00
Hawke’s Bay 0.84 2.75 -1.90
Manawatu -2.66 -10.32 7.70
Wellington -2.74 10.16 -12.90
Otago -3.98 -1.45 -2.50
Northland -4.42 -8.22 3.80
Waikato -5.74 -1.20 -4.50
Southland -6.31 -5.85 -0.50
Bay of Plenty -9.23 -5.47 -3.80
North Harbour -10.13 -9.77 -0.40

 

Performance So Far

So far there have been 70 matches played, 44 of which were correctly predicted, a success rate of 62.9%.

Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Counties Manukau vs. Auckland Oct 08 41 – 18 1.40 TRUE
2 Waikato vs. Bay of Plenty Oct 09 29 – 12 5.70 TRUE
3 Otago vs. Manawatu Oct 10 25 – 38 5.40 FALSE
4 Wellington vs. North Harbour Oct 11 58 – 34 9.10 TRUE
5 Hawke’s Bay vs. Southland Oct 11 20 – 20 13.20 FALSE
6 Auckland vs. Northland Oct 11 38 – 10 13.60 TRUE
7 Taranaki vs. Canterbury Oct 12 23 – 26 -5.00 TRUE
8 Tasman vs. Counties Manukau Oct 12 16 – 21 12.40 FALSE

 

Predictions for the ITM Cup Finals

Here are the predictions for the ITM Cup 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.

Game Date Winner Prediction
1 Hawke’s Bay vs. Northland Oct 17 Hawke’s Bay 9.30
2 Manawatu vs. Southland Oct 18 Manawatu 7.70
3 Taranaki vs. Auckland Oct 18 Taranaki 3.00
4 Tasman vs. Canterbury Oct 18 Tasman 1.30

 

October 14, 2014

Does it make any more sense this time?

From the Herald today

“The average annual weekly wage increase of $28.06 was not enough to offset a $30,000 increase in the national median house price and an increase in the average mortgage interest rate from 5.52% to 5.86%,” the survey found.

We did this one last time, in June. Today’s story is better in that it links to the Massey report. It could still do with a bit of interpretation.

Quick, without a calculator, roughly what would be a large enough weekly wage increase to offset a $30,000 increase in the national median house price?  Would we need to up the $28.06 by ten percent, or  ten dollars, or a factor of ten?

[Update: I should also note that the word “weekly” wasn’t in the description of wage increases last time, so this is a definite improvement]

Ada Lovelace Day

October 14 is Ada Lovelace Day, an international celebration of the achievements of women in science, technology, engineering and maths.

New Zealand has (only) three female Professors of Statistics, the top position in our UK-style academic ranking. They work in very different areas of statistics, but with related applications to ecological and environmental monitoring, an area of particular interest in New Zealand.

Going north to south:

  • Marti Anderson is at Massey University in Albany (and was previously at the University of Auckland). Her research is in multivariate analysis — techniques for analysing ecological data on multiple species together, rather than one at a time — mostly applied to marine species
  • Shirley Pledger retired this year from Victoria University. Her research is on capture-recapture methods for counting animals. It’s often impossible to get a complete census of a species even in a limited area, but you can mark the individuals you catch, release them, and observe how often you catch them again. The simplest approaches to estimation are easy but unrealistic; she has worked on more sophisticated and sensible models.
  • Jennifer Brown is head of the Maths & Stats department at the University of Canterbury. Her main statistical research is on sampling techniques for monitoring sparse or patchy populations: either rare animals and plants, or invasive weeds. Sampling systematically or purely at random are both very wasteful; ‘adaptive’ sampling designs allow you to take advantage of finding a clump of your target species without biasing the overall results.

 

October 10, 2014

Briefly

  • Something strange happened to this month’s unemployment data in Australia: Guardian, ABC News, interview with Rob Hyndman (who knows from time series)
  • “Ferguson’s 3,287 new registrants (in two months) is more than recorded by any township in St. Louis County in any midterm election since 2002.” Or not. A number that seems really extreme may just be wrong.
  • When there’s a lot of variation, it can be a mistake to make statements about “typical” attitudes: Andrew Gelman
October 8, 2014

Communicating the obvious (to you)

From the Herald

People’s coffee-drinking habits are linked to their genes, scientists say.

A large-scale study, which analysed 20,000 regular coffee drinkers of European and African American ancestry, identified six new genetic variants associated with habitual coffee drinking.

What the story (and the press information) doesn’t say is how small the effects are: among regular coffee drinkers, each of these variants predicted a difference in average consumption of one or two cups per month. (research paper, paywalled)

The  researchers would think it’s obvious that the effects are going to be tiny, so it makes sense that they wouldn’t point this out explicitly. The journalists and publicists wouldn’t know, but there’s no reason they would think to ask.

October 7, 2014

Currie Cup Predictions for Round 10

Team Ratings for Round 10

The basic method is described on my Department home page. I have made some changes to the methodology this year, including shrinking the ratings between seasons.

Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Current Rating Rating at Season Start Difference
Western Province 7.02 3.43 3.60
Lions 4.39 0.07 4.30
Sharks 3.35 5.09 -1.70
Blue Bulls -0.18 -0.74 0.60
Cheetahs -1.89 0.33 -2.20
Pumas -7.97 -10.00 2.00
Griquas -8.90 -7.49 -1.40
Kings -15.13 -10.00 -5.10

 

Performance So Far

So far there have been 36 matches played, 27 of which were correctly predicted, a success rate of 75%.

Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Sharks vs. Lions Oct 03 26 – 23 4.10 TRUE
2 Pumas vs. Blue Bulls Oct 03 6 – 37 0.80 FALSE
3 Cheetahs vs. Western Province Oct 04 29 – 34 -3.70 TRUE
4 Griquas vs. Kings Oct 04 45 – 25 10.00 TRUE

 

Predictions for Round 10

Here are the predictions for Round 10. 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.

Game Date Winner Prediction
1 Kings vs. Pumas Oct 10 Pumas -2.20
2 Lions vs. Cheetahs Oct 11 Lions 11.30
3 Western Province vs. Sharks Oct 11 Western Province 8.70
4 Blue Bulls vs. Griquas Oct 11 Blue Bulls 13.70

 

ITM Cup Predictions for Round 9

Team Ratings for Round 9

Here are the team ratings prior to Round 9, 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.

Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Current Rating Rating at Season Start Difference
Canterbury 13.83 18.09 -4.30
Tasman 12.17 5.78 6.40
Auckland 6.43 4.92 1.50
Taranaki 4.87 -3.89 8.80
Counties Manukau 3.79 2.40 1.40
Hawke’s Bay 1.86 2.75 -0.90
Otago -2.60 -1.45 -1.20
Northland -3.21 -8.22 5.00
Wellington -3.87 10.16 -14.00
Manawatu -4.03 -10.32 6.30
Waikato -6.62 -1.20 -5.40
Southland -7.33 -5.85 -1.50
Bay of Plenty -8.35 -5.47 -2.90
North Harbour -9.00 -9.77 0.80

 

Performance So Far

So far there have been 62 matches played, 39 of which were correctly predicted, a success rate of 62.9%.

Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Hawke’s Bay vs. Wellington Oct 01 36 – 14 9.00 TRUE
2 Auckland vs. Waikato Oct 02 60 – 19 13.00 TRUE
3 Northland vs. North Harbour Oct 03 58 – 27 6.20 TRUE
4 Southland vs. Counties Manukau Oct 04 10 – 24 -5.80 TRUE
5 Bay of Plenty vs. Otago Oct 04 33 – 16 -5.00 FALSE
6 Canterbury vs. Tasman Oct 04 10 – 38 11.10 FALSE
7 Manawatu vs. Hawke’s Bay Oct 05 29 – 3 -5.50 FALSE
8 Wellington vs. Taranaki Oct 05 22 – 38 -1.70 TRUE

 

Predictions for Round 9

Here are the predictions for Round 9. 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.

Game Date Winner Prediction
1 Counties Manukau vs. Auckland Oct 08 Counties Manukau 1.40
2 Waikato vs. Bay of Plenty Oct 09 Waikato 5.70
3 Otago vs. Manawatu Oct 10 Otago 5.40
4 Wellington vs. North Harbour Oct 11 Wellington 9.10
5 Hawke’s Bay vs. Southland Oct 11 Hawke’s Bay 13.20
6 Auckland vs. Northland Oct 11 Auckland 13.60
7 Taranaki vs. Canterbury Oct 12 Canterbury -5.00
8 Tasman vs. Counties Manukau Oct 12 Tasman 12.40

 

October 6, 2014

Is Jon Snow dead?

From Richard Vale, at University of Canterbury

What’s this? You are claiming that we can use Bayesian statistics to predict Game of Thrones?
Probably not, no.

But we can try?
Yes!

Further coverage, and his full article

(via Dion O’Neale)