'The data will almost certainly be biased' - Macleans.ca

‘The data will almost certainly be biased’

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New figures show a 69% response rate for the National Household Survey—higher than Statistics Canada expected, but still not sufficient to replace the long-form census.

“You simply can’t get reliable data from a voluntary survey,” said John Brewster, who teaches statistics at the University of Manitoba and is president of the Statistical Society of Canada. “I mean, this is something we teach in every course in statistics, for example. The data will almost certainly be biased. And we don’t really know at this time the magnitude or direction of that bias.”