The "donut" effect

In several census metropolitan areas, the population in the core municipality is growing more slowly than in the areas around it forming a donut. The larger the difference in the growth between the two, the more pronounced the "donut effect". This phenomenon was particularly prominent in census metropolitan areas such as Saskatoon and Regina.

The population of the core municipality of the CMA of Saskatoon increased 1.6% between 1996 and 2001, while the other municipalities around this core increased 14.6%. Similarly, the population of the core municipality of the CMA of Regina declined 1.2%, while the municipalities surrounding it incurred a 10% increase.

If the 27 census metropolitan areas are considered as a group, the population of their core municipalities increased 4.3% between 1996 and 2001. This was one-half the growth rate of their surrounding municipalities (+8.5%).

The growth in these surrounding municipalities has been fuelled by migration and natural increase, as young families choose to live and raise children in suburbs. Seventeen of the 25 fastest-growing municipalities in Canada are those that surround the core of census metropolitan areas.

On the other hand, the opposite occurred in the census metropolitan areas of Abbotsford and Ottawa-Hull, where growth was higher in the core than in the municipalities surrounding them.