The general concept of a census metropolitan area (CMA) is one of a very large urban area, together with adjacent urban and rural areas which have a high degree of economic and social integration with that urban area. A census metropolitan area is delineated around an urban area (called the “urbanized core”) and has a population of at least 100,000 (based on census counts).
The list of CMAs need not remain static. New CMAs can be added, when the census population counts and the level of economic and social integration warrant. The CMAs of Barrie and Kelowna were added as a result of the 2006 Census results.
Postcensal estimates at the CMA level are produced according to three time-frames of availability: preliminary, updated, and final estimates. For some components (e.g., births and deaths), the data sources used for provincial/territorial estimates of population provide data at CMA levels, whereas other components must use a combination of different data sources for this level of estimation (e.g., immigration).
CMA estimates of population are produced using the component method. The use of the component method for preliminary estimates at subprovincial levels is quite new, commencing with the 2001 series. Prior to this, two other methods were used (during different timeframes) – the rate of growth method (used for preliminary estimates covering 1998 to 2001) and the regression-nested model (used prior to 1998).
CMA final, updated and preliminary estimates of population are obtained using the component approach. The adjustment to the base population for net census undercoverage is done by applying the provincial and territorial rates by single year of age and sex. Since CMA boundaries do not remain stable over time, estimates of population and components are adjusted to respect the boundaries defined in the most recent census. This ensures a stable base population for all estimates. In the estimation of migration, an additional component, subprovincial migration, (i.e., migration within provinces/territories and across subprovincial areas) is necessary.
Prior to generating the population estimates, the total provincial/territorial population counts and the components for Census Divisions (Census Divisions are areas such as divisions, counties, regional districts, regional municipalities) and CMAs are calibrated, if necessary, to assure consistency between the two sets of figures.