[LINK] "Government study reveals significant errors in voluntary census "

[rfmcdonald]

The Globe and Mail's Steven Chase reveals the unsurprising news.

A June, 2010, internal study obtained by The Globe and Mail under the access-to-information law offers an inside look at how new census-taking rules could skew data in a range of areas from housing to demographics.

Statistics experts warn its findings demonstrate how minorities and groups such as renters could be measurably underrepresented or miscounted in the coming 2011 census.

The Statscan study, Potential Impact of Voluntary Survey on Selected Variables, was prepared with full knowledge of Ottawa’s census change plans. It attempts to re-create what the 2006 long-form census questionnaire would have yielded had respondents not been compelled to answer it. These simulated results were contrasted with real 2006 census data.

Statscan researchers found the voluntary approach produced less accurate results – a problem that was especially significant in small population groups, according to outside statistics advisers who reviewed the report for The Globe.

[. . .]

For instance, the real 2006 census long-form found that renting households as a percentage of the population in Canada had dropped by 3.08 percentage points from the 2001 census.

But when the Statscan study simulated the results of a voluntary 2006 long-form – which reflect the lower response rates expected in optional surveys – it got a markedly different answer. Calculations instead indicated that rented dwellings in Canada as a share of the population declined by 8.07 percentage points from 2001.

[. . .]

In another example from the report, the real 2006 long-form census found that visible minorities as a share of the population increased by 2.77 percentage points between 2006 and 2001. The simulated voluntary approach would have reported an increase of only 0.74 percentage points.