Posts tagged Winner (55)

July 1, 2013

Stat of the Week Winner: June 22 – 28 2013

Congratulations to Nick Iversen for his nomination of this stat of the week from the NZ Herald:

This story states that “Public opinion has turned …” To justify this they quote statistics from surveys done in 1012 and 2103.

But the surveys are not comparable. They asked different questions.

The 2012 survey questions and results:

I disapprove 40.3%
I approve 19.6%
I conditionally approve 37.7%

The 2013 survey questions and results:

I disapprove 61.5%
I approve 33.8%

When the condition (that the number of pokie machines drops across the city) was removed from the 2013 survey those respondents had to switch to a new answer.

My guess is that most would have switched to “I disapprove” because their approval was conditional and the condition has now been removed. If so then the 2012 survey would have had results:

I disapprove 78.0%
I approve 19.6%

In that case public opinion has moved in the opposite direction to that in the headline.

Even if only half would have switched the figures would have been

I disapprove 59.2%
I approve 38.5%

and it still looks like the opposite to the headline.

The headline is pure fiction. The numbers don’t support it. The two surveys can’t be compared.

For more, see Thomas’ post on this.

May 20, 2013

Stat of the Week Winner: May 11-17 2013

Congratulations to Simon Connell for his nomination of this stat of the week from the Otago Daily Times:

“In a three-month trial in Manukau [of an automatic number plate recognition unit], police recovered 15 stolen vehicles, took 180 disqualified, forbidden or suspended drivers off the road, and recovered stolen property from various offenders, [Southern District acting road policing manager Senior Sergeant Steve Larking] said.

”So the benefits are clear.””

Simon makes an excellent point about evidence:

“I’m not sure if this is strictly a statistic or not, but this story (which reads like a copy/paste from a press release) seems to accept without question the benefits of the automatic number plate recognition unit.
We can’t actually make any assessment of the benefits of the unit without some information about how many stolen cards would have been recovered etc. without the unit installed. It does seem like the unit is useful, but it’s hard to judge whether or not it’s worth the $40-$50k price tag without further information.”

April 29, 2013

Stat of the Week Winner: April 20 – 26 2013

Congratulations to Tony Cooper for his nomination for Stat of the Week:

Statistic: New Zealand has been placed 26th out of 68 countries in a global ranking of life expectancy in retirement.

The Bloomberg data is wrong. They have incorrectly calculated “average number of years residents of 68 countries around the world can look forward to after they stop working.”

It’s a Bloomberg story but the data is being reproduced in NZ for Kiwisaver investors. For example http://media.gmi.co.nz/mailouts/morganOnline/2013/MorganOnlineApr2013.htm.

What Bloomberg have done is subtract the average age of retirement from the life expectancy at birth to calculate “sunset years.” For example, for NZ males this is 78.8 – 65 = 13.8.

But according to NZ Stats Dept figures released last week the life expectancy for NZ males at 65 is 18.8 – a big difference.

The error that Bloomberg made is that you can’t calculate life expectancy at age 65 from the life expectancy at birth. 65 year-olds have a better life expectancy than newborns since they have survived 65 years whereas newborns have a chance of dying before 65.

April 22, 2013

Stat of the Week Winner: April 13 – 19 2013

Congratulations to Steve Black for his highly topical nomination for Stat of the Week:

Statistic: A bogus txt in poll on Campbell Life shows 22% support for the same sex marriage bill, 78% opposed.
Source: TV3 Campbell Live
Date: 17 April 2013

A bogus txt in poll on Campbell Life shows 22% support for the same sex marriage bill, 78% opposed. Nice illustration of just how far off bogus polls can be from general population results done by proper sampling techniques. Ironically, it came on the same day as the legislation passed 77 to 44. I can’t find a trace of it left on the TV3 web page, but I’m still collecting references. Note that the conservative blog I referenced considers it “The best indication yet, short of a referendum, of what the public actually think about same-sex marriage.” thus compounding the mistake of bogus polls taken as meaningful.

This bogus poll would be a perfect example for our first year introductory statistics course on non-sampling errors causing biased results.

Special mention also to Nick’s nomination of Statistics New Zealand’s latest New Zealand Period Life Tables.

April 8, 2013

Stat of the Week Winner: March 30 – April 5 2013

Congratulations to Nick Iversen for his humorous nomination of “Sex basically doubles your life span” winning this week’s Stat of the Week competition:

“The anti-ageing benefits [of frequent sexual activity] are amazing. It basically doubles your life span once you get to your 60s and 70s.”

The article obviously get correlation confused with causation but that’s not why I’m posting it here.

The reason for the post is that the statement about life span is so obviously blatantly wrong that I don’t see how any intelligent person could make it.

The average life span of people in their 60s and 70s is (funnily enough) at least 60 or 70. Doubling this means that sex extends your lifespan to 120 or 140.

OK so she really means “remaining lifespan.” For those in their 60s remaining lifespan is about 20 to 25 years. So frequent sex doubles that to 40 to 50 years.

Just doesn’t sound at all reasonable to me. If sex makes that much difference to life expectancy it far outweighs any contributions due to diet, exercise etc and would have been noticed centuries ago.

March 25, 2013

Stat of the Week Winner: March 16 – 22 2013

Congratulations to David Farrar for his nomination last week in our Stat of the Week competition.

He nominated this table on the NZ Herald (click to enlarge the screenshot):

Herald Poll Table

We liked that the Herald were quick to fix the mistake after being alerted of it, but it would have been helpful to also include a note that it had been updated since published.

Thomas Lumley commented that while the totals were just a mistake, not a premeditated misuse, the whole table was a bad idea.

March 4, 2013

Stat of the Summer Competition Winner!

Thank you for all the fantastic Stat of the Summer nominations.

Congratulations to Jonathan Goodman for winning a copy of Tufte’s book “Beautiful Evidence” whose nomination explained and neatly summarised the NZ Herald article “Women with more sex partners turn to drink and drugs”:

“The title and the first paragraphs make the statements that the more promiscuous you have been in the past, the more likely you are now to be dependent on drugs and alcohol. That being promiscuous causes dependency.

“Women who averaged more than 2.5 sexual partners a year in the years leading up to each interview with the researchers were 10 times as likely as women who had only one or no sexual partners a year to be clinically dependent on alcohol or drugs at age 21. They were seven times as likely by age 26 and 17 times as likely by age 32, even after allowing for all other factors in their lives.”

The increase in likelihood of dependence as the number of years of promiscuity increases is seen as evidence that promiscuity causes alcohol and drug dependence.

However the article then paraphrases the researches by saying “The researchers said the link between the number of partners and later substance dependence might be due to the “shared context” of drinking and meeting people in bars, or to both behaviours being related to underlying risk-taking attitudes.”

While the author of the article claims in the title that researchers have found that promiscuous activities drives people to drink and drugs, all the researchers have found out is that there is a correlation between the two. As we all know Correlation does not imply Causation.”

Thank you to everyone who took part and we are now resuming our weekly competition, so please keep your nominations coming in!

December 10, 2012

Stat of the Week Winner: December 1-7 2012

Thanks for your nominations last week in our Stat of the Week competition. We’ve selected Daniel Croft’s nomination of fascinating text message statistics on the advent of 20 years of text messaging:

“Wednesday was the 20 year anniversary of the first text message to have been sent, and so in response both Telecom and Vodafone have released some surprising information.

“Vodafone users sent 7.3 billion texts last year while Telecom was just under 7 billion. Thats 14,000,000,000 plus texts a year. Thats 38,000,000 a day spread between a population of 4,400,000… 8 texts per person a day. Or 2920 texts per person a year.

“A statistic that I would love to hear on this would be just how many of those 14 billion texts are just ‘LOL’.”

(A reminder that in our competition fine print, we state that we will not award Stat of the Week for a statistic coming from anyone at the University of Auckland outside the Statistics department. You can still nominate and discuss them, but the nomination won’t be eligible for the prize.)

December 3, 2012

Stat of the Week Winner: November 24 – 30 2012

Congratulations to Eva Laurenson for her excellent nomination of the NZ Herald’s article entitled “Manukau ‘luckiest’ place for Lotto”:

What does ‘luckiest’ in this title mean? Well to the average person ( I asked a few) they interpreted that title as ” I would have a higher chance of winning Lotto if I bought my ticket from a Manukau store compared to another store from a different suburb in Auckland.” Is this really the case? I doubt it. The article ranks Manukau ‘luckiest’ because it is the suburb with the highest total paid out first division amount. However no where did they take into account the total sales of Lotto tickets in each suburb. I think if you took this into account you’d see that Manukau sells alot more tickets than some of these other suburbs in Auckland. So even though Manukau can boast 55 mil in first division prizes we have no idea whether that is 55 mil out of 100 mill worth of ticket sales or 55 mil out of 1 bill worth of ticket sales. Some of the other suburbs may have a lesser amount of first division payouts compared to Manuaku but could have a greater proportion of first division payouts compared to ticket sales. Hence if that was true, your chance of winning first division given that you bought your ticket in that other suburb would be greater than (the same probability measured for) Manukau. Therefore I think there isn’t sufficient information provided to make this claim.

What I think the article could say is ‘given I won first division, the chances that I bought my ticket in Manukau are ____ times the chance that I bought it somewhere else.’ Something to this effect could be derived from the information presented by the herald article and it makes a bit of sense. Is this what the article wrote though? Not at all. They summarised this finding into “Manukau is the luckiest Lotto suburb in Auckland.” Please! This screams misleading. As discussed above, there simply isn’t enough information to justify labelling Manukau the ‘luckiest’ suburb for Lotto. People have a clear idea of what it means to be lucky and that generally is that they have an increased chance of winning. This is not the conclusion you can draw from the information they provided and in this case I believe the herald got it wrong.

I also think, although probably not the authors intentions, labelling Manukau as the ‘luckiest’ suburb has the danger of enticing people to spend more on Lotto. This article published earlier in the year by the NZ herald noted that “Many South Auckland suburbs featured among those which gambled away the most money. Mangere Bridge, Flat Bush, Manukau and Manurewa were in the top dozen suburbs.”
Even though the article was talking about the pokies, Lotto is just another form of gambling. We shouldn’t be condemming one and sending a rosy message about another, especially to communities who are struggling as it is.

Overall I think this should be the Stat of the week because using ‘lucky’ was a nice little pun but in effect mislead people regarding their chances of winning first division depending on where they bought their ticket.

Secondly it seems wrong to label a suburb ‘luckiest’ and potentially encourage a community to spend more on Lotto there when it is known that it is a compartively poorer area than other Auckland suburbs and spends alot of money on gambling as it is.

Thomas expanded on this, saying:

This looks as if it’s claiming that tickets bought in Manukau have been more likely to win. If this was true, it would still be useless, because future lotto draws are independent of past ones.

It’s even more useless because there is no denominator: not tickets sold, not people in the suburb, not even number of Lotto outlets in the suburb.

What the statistic, and the accompanying infographic, really identifies is the suburbs that lose the most money on Lotto. That’s why Manukau and Otara are ‘lucky’ and Mt Eden and Remuera are ‘unlucky’, the sort of willfully perverse misrepresentation of the role of chance that you more usually see in right-wing US outlets.

October 15, 2012

Stat of the Week Winner

Congratulations to Andrew Mardon for being this week’s Stat of the Week winner for his nomination of:

“The higher a country’s chocolate consumption, the more Nobel laureates it spawns per capita, according to findings released in the New England Journal of Medicine.”

While the article mentions both correlation and causation, it doesn’t clearly explain the difference between the two and makes the distinction murkier by saying science is fallible and including a gem quote such as this:

“[The US] would have to up its cocoa intake by a whopping 125 million kg a year to produce one more laureate, said Franz Messerli, who did the analysis.”