Posts written by Rachel Cunliffe (180)

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Rachel Cunliffe is the co-director of CensusAtSchool and currently consults for the Department of Statistics. Her interests include statistical literacy, social media and blogging.

March 10, 2014

Stat of the Week Competition: March 8 – 14 2014

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 March 14 2014.
  • Statistics can be bad, exemplary or fascinating.
  • The statistic must be in the NZ media during the period of March 8 – 14 2014 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.

(more…)

Stat of the Week Competition Discussion: March 8 – 14 2014

If you’d like to comment on or debate any of this week’s Stat of the Week nominations, please do so below!

March 3, 2014

Stat of the Week Competition: March 1 – 7 2014

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 March 7 2014.
  • Statistics can be bad, exemplary or fascinating.
  • The statistic must be in the NZ media during the period of March 1 – 7 2014 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.

(more…)

Stat of the Week Competition Discussion: March 1 – 7 2014

If you’d like to comment on or debate any of this week’s Stat of the Week nominations, please do so below!

January 29, 2014

Using statistics to fight crime

“I want to ‘Money Ball’ criminal justice” – Anne Milgram

Fascinating video from TED.

“When she became the attorney general of New Jersey in 2007, Anne Milgram quickly discovered a few startling facts: not only did her team not really know who they were putting in jail, but they had no way of understanding if their decisions were actually making the public safer. And so began her ongoing, inspirational quest to bring data analytics and statistical analysis to the US criminal justice system.

Anne Milgram is committed to using data and analytics to fight crime.”

December 10, 2013

It’s all in the definition

The most-read story on the NZ Herald right now is “Cost of home dream in Auckland – 19 incomes. Only six months ago, the NZ Herald published an infographic which showed that a median house costs 6.9 times the annual median household income in Auckland. It’s enough to make anyone confused.

The new article says:

“It would take 19 median incomes in Auckland to buy a home for the city’s median house price.

In the 1,119,195 Census forms filled out for Auckland, the median annual income was $29,600, a Herald analysis found.”

I checked with the Stats NZ Census figures (Excel spreadsheet) and found the $29,600 figure is for the usually resident population count aged 15 years and over. In other words, this includes everyone who is not in paid employment: all the students, retirees, parents who are staying at home, those on benefits and not working etc.

Using Statistics New Zealand’s income survey data for the June 2013 quarter (Excel spreadsheet), the median earnings for people in paid employment was $45,864. This figure is only from those earning wages and salaries and/or self-employment income.

Strictly speaking, the median house price we’re comparing to should be for the same period but for now, I’m using the June 2013 median Auckland house price from the Real Estate Institute (PDF): $555,000.

This means the statement could be revised to:

“It would take 12 median incomes in Auckland to buy a home for the city’s median house price.”

However, this misses the point that the accepted method is to look at median household incomes. Statistics New Zealand recommends a more complex calculation:

The ratio of housing cost to income is often used as a way of measuring affordability. Here, the ratio is calculated as housing cost as a proportion of disposable household income (income after tax). A housing cost to income ratio of 25 percent has been used as a threshold for the purpose of comparing groups. This threshold is widely used both nationally and internationally.

Again, using Statistics New Zealand’s income survey data for the June 2013 quarter, the median household income was $70,616 for the Auckland region (NZ.STAT tool).

This means the statement could be revised to:

“It would take 7.9 median household incomes in Auckland to buy a home for the city’s median house price.”

Comparing simple figures from New Zealand with overseas without taking into consideration tax and the cost of living really isn’t meaningful. Further, the mixing of means and medians means that they are not comparing like with like…

It’s easy to use figures to make things seem much worse than they actually are.

December 9, 2013

Stat of the Week Competition: December 7 – 13 2013

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 December 13 2013.
  • Statistics can be bad, exemplary or fascinating.
  • The statistic must be in the NZ media during the period of December 7 – 13 2013 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.

(more…)

Stat of the Week Competition Discussion: December 7 – 13 2013

If you’d like to comment on or debate any of this week’s Stat of the Week nominations, please do so below!

December 2, 2013

Stat of the Week Competition: November 30 – December 6 2013

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 December 6 2013.
  • Statistics can be bad, exemplary or fascinating.
  • The statistic must be in the NZ media during the period of November 30 – December 6 2013 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.

(more…)

Stat of the Week Competition Discussion: November 30 – December 6 2013

If you’d like to comment on or debate any of this week’s Stat of the Week nominations, please do so below!