As expected, the Census counts, released today for May 1996, are lower than the population estimates published by the Agency. This note outlines why there are differences between Census counts and the population estimates.

The objective of every Census is to provide detailed information at a single point in time on the demographic, social and economic conditions of the population. One of its goals is to enumerate the entire population on Census Day. Inevitably, however, some people are not counted, either because their household did not receive a Census questionnaire (for example, a household living in a separate apartment in a house) or because they were not included in the questionnaire completed for the household (for example, a boarder or lodger). Some people may also be missed because they have no usual residence and did not spend census night in any dwelling. On the other hand, a small number of people may also be counted twice (for example, a student living away from home).

To determine how many individuals were missed, or counted more than once, Statistics Canada conducts post-censal coverage studies of a representative sample of individuals. The results of these studies provide information which is used to adjust the Census counts for the purpose of producing current (quarterly and annual) population estimates which take into account net under-enumeration in the Census.

In 1991, after adjustment for net under-enumeration, the population estimate for Canada was 2.9% higher than the population enumerated in the Census. The studies of the completeness of enumeration of the 1996 Census will be completed in May, 1998, and will be used to revise and update the population estimates.

In studying trends in population growth between the 1991 and 1996 censuses, it is quite appropriate to compare census counts from the two censuses. In most cases, the results will be similar to trends shown by the national and provincial population estimates, since the measurement of growth is affected very little by net undercoverage. The advantage of the Census is that it allows comparisons to be made for cities, towns and small communities for which detailed population estimates are unavailable. And, of course, the Census provides a wealth of information about the population (language, ethnic origin, education and labour force activity) which is not available from any other sources.