Thursday, September 22, 2011

"On October 6th vote for proper scaling of the Y-axis. Vote Liberal."


For those worried the Ontario election lacked a meaty ballot questions, comes the most exciting statistical controversy since the scrapping of the mandatory long form Census:


There are 13 statistical graphs in the Changebook. Every single one reveals significant errors in labelling, citation, scaling, and proportion. In a few cases, the illustrated data is actually false. In almost all, axes and scaling have been skewed and manipulated, without proper labelling, to exaggerate political points. In some cases, it appears the graphs were simply hand-drawn.

Whatever one thinks of a political party’s platform, voters have the right to expect honesty and transparency in its presentation. The consistent pattern of distortion in the Changebook’s 13 graphs reveals a willingness to sacrifice integrity for political optics. And that approach is consistent with the other controversies that have dogged the Conservative campaign so far.


Yup. 0 for 13. That's 0%. Or, as the Changebook writers would express it:

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Saturday, July 03, 2010

In those days Caesar Augustus issued a decree that a census should be taken of the entire Roman world...among those who felt like it

I know this isn't a big issue. I don't expect facebook groups and protests in the streets over it. But, as someone who worked on the Census in the past, this really grates me:

Former StatsCan head slams census decision by Tories

OTTAWA - The former chief statistician of Canada says he would have quit his job if the Conservative government had tried to axe the long census form, as they're doing now.

Ivan Fellegi, a veteran public servant who spent 51 years at Statistics Canada before retiring in 2008, says he's alarmed by the decision to replace the long census form with a voluntary survey next year.

He joins a chorus of groups, including the Federation of Canadian Municipalities, the Canadian Council on Social Development and others who rely on the detailed data to make major public policy decisions.

"It would have been a heck of a lot better if this long-form census was cancelled because at least we would have saved $100 million — that would have had a rationale," Fellegi said in an interview with The Canadian Press.

"To come out with something (voluntary) that has uncertain quality, and certainly for some groups it will be unpublishable quality, is not something that I can understand."

The mandatory short census, with its basic questions on the ages and sexes of people in a household remains unchanged. But one-third of Canadians, up from one-fifth, will now receive a voluntary "national household survey" with detailed questions on ethnicity, education and income similar to those on the long census.

The cost of the change could reach $30 million, says Statistics Canada: $5 million for the additional mailout, and $25 million in case there is a major problem in getting people to respond.


The problem is that once you make the form voluntary, the sample becomes self-selecting, losing its randomness and, by consequence, its representativeness. The bottom line is that certain types of people will be more likely to fill out their form, skewing the results.

You'll get far more accurate data from 1/5 of all households than you will from the 1/3 of all households that bother to complete their form. It's the same reason why you get better data from a scientific telephone poll of 1,000 Canadians, than you do from the 10,000 people who vote on the Globe and Mail's web poll.

Census data is used for everything from municipal governments deciding where to build schools, to entrepreneurs deciding where to open up new restaurants. Making the long form voluntary will compromise the data used to make thousands of public and private sector decisions.

Yeah, I know data collection isn't sexy. But it's important. This decision needs to be reviewed.

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