Differences between Statistics Canada's census counts and population estimates

The 2011 Census counted 33,476,688 people in Canada during the national enumeration with reference date May 10, 2011. This count is lower than the population estimate of 34,444,320 people calculated for the same reference date. The difference between the two figures is not unexpected and is similar to that which was experienced in the 2006 Census. This note outlines why there are differences between census counts and population estimates.

The objective of a census is to provide detailed information on the population at a single point in time. In this respect, one of its goals is to enumerate the entire population. Inevitably, however, some people are not counted, either because their household did not receive a census questionnaire (for example, if a structurally separate dwelling is not easily identifiable) or because they were not included in the questionnaire completed for the household (for example, the omission of a boarder or a lodger). Some people may also be missed because they have no usual residence and did not spend census night in any dwelling. In contrast, a small number of people may also be counted more than once (for example, students living away from home may have been enumerated by their parents and by themselves at their student address).

To determine how many individuals were missed or counted more than once, Statistics Canada conducts postcensal coverage studies of a representative sample of individuals. Results of these studies in combination with the census counts are used to produce current population estimates which take into account net undercoverage.

For the 2011 Census, final coverage studies have been released on September 26, 2013. In turn, these have been used to revise and update the population estimates based on the 2011 Census results. Consequently, a series of revised population estimates for the period 2006 to 2013 has been released on September 26, 2013.

One of the advantages of the census is to provide counts for small regions (below the census division level) for which demographic estimates are not available or are less precise. On the other hand, population estimates provide a more accurate measure of population counts. In addition, estimates are utilized to measure the evolution of the population between censuses and provide explanations behind the population growth. They are available on a quarterly and annual basis at the national, provincial and territorial levels and are also available at the subprovincial level on an annual basis.