Repeat After Me, Tony, “but… Algeria!”
July 15, 2010 | 1 Comment
Yeah, I’m going to try to make this thing stick.
Tony Clement, our beloved Industry Minister, has found himself caught in a census trap. For those who haven’t been following what is, essentially, When Math Nerds Attack, the new Canadian census is ditching the mandatory aspect of the mandatory long form. This time ’round, the long form will be voluntary. Mr. Clement has been pilloried by those who value useful and accurate statistics, and he just won’t back down:
Industry Minister Tony Clement says he’s willing to testify before a House of Commons committee about his decision to scrap the mandatory long-form census – a move the the Canadian Medical Association Journal decries as an example of “ideology trumping evidence.”
Rather than just scrapping the mandatory long form, or making it shorter, the government has decided to make responding to the long form voluntary. Knowing that this could severely reduce the number of respondents, they hoped to balance that out by sending the form out to more Canadians. Although this will help to ensure a high number of responses, the responses will, likely, be less representative, and thus less accurate.
There has been a chorus of critics pointing out that this move makes the census rather useless. It’s a matter of selection bias. When participants in this sort of survey are allowed to self-select, the respondents are no longer sufficiently random to be a proper cross-section of the population at large. If there is a certain portion of the population that is more likely to respond to a request from the government to complete and return the voluntary long form, that group will be over-represented in the results. It’s a basic statistical phenomenon.
The governments coping mechanism, to send the form to one third of households rather than 20%, will do nothing to address the selection issue. It’s akin to saying, sure we lose money with each product we sell, but we make up for it in volume! This is just not how mathematics works.
I’m sympathetic to the notion that the census is ridiculously intrusive. If the government wishes to lessen this intrusion, that’s fine, but two things: First, shorten the thing and make it mandatory, so there’s some value to the numbers. Second, don’t insult our intelligence by pretending that you haven’t just gamed the census by making participation voluntary.
Sadly, Mr. Clement underscores his fumbling of this matter:
“Just in the past 48 hours I’ve received dozens and dozens of [letters from] Canadians who despite the adverse publicity … have come forward and said, ‘We agree with your position,’” Mr. Clement said.
Anecdotes are not data, sir, and if you won’t understand that, you should have no control over the census.
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July 16th, 2010 @ 8:18 am
What a maroon.
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