When it comes to the census, who is counted and who isn’t matters.

The 2021 Census counted 36,991,981 people in Canada during the national enumeration with reference date May 11, 2021. This count is lower than the preliminary postcensal population estimate of 38,201,103 people calculated for the same reference date. The difference between the two figures is not unexpected and is similar to that which was experienced for previous censuses. 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 separated 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).

When using Statistics Canada census data, keep in mind that the total population indicated in the census is not the actual total population of an area or geography).

Like other data gathering tools, censuses are not perfect sources of information. When the census is conducted, there is room for error and residences to not be accounted for. Missing data in census counts is called “undercoverage”.

To help cope with this issues, Statistics Canada estimates an “undercount” or “undercoverage” rate to assist estimating the real total population. Undercount rates are typically provided for each Census Metropolitan Area in the country…

The difference between the total and the Census Population [for Peel Region] is significant: over 60,000 people. More people than were reported in Caledon alone for 2006!

When planning for services, keep undercounts in mind!

The 2021 Census reported that from 2011 to 2021, Ontario’s population grew by 10.7 per cent and the number of occupied dwellings grew by 12.5 per cent.

These results are a reminder that some caution must be used with census data. O’Hare (2019) reported that a relatively low CNU rate can hide significant undercoverage or overcoverage as well as large differences between demographic groups. Furthermore, coverage errors are not calculated for all characteristics available in censuses, so coverage for certain groups likely to be less well covered, like less educated individuals or those with lower incomes, is not well known.

Harder-to-enumerate populations often face physical, economic, social and cultural barriers.



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