Projections of Population Growth
Population projections were developed for each of the 16 Census Divisions in the Greater Golden Horseshoe, for the 2001-to-2031 period. A summary of the projections is provided here. The details are shown in Appendix A.2.
The projections use a "cohort-survival" method, the most commonly used approach for developing long-term projections of population. The model employs the following steps:
- Starting in the base year of the analysis, data are obtained on population by single year of age, by sex. In this case, the data are for July 1, 2001. The database can be drawn either from the 2001 census, or from Statistics Canada's post-censal estimates. The main difference between these two data sets is that the census data do not include 100 percent of the population, as some people are missed by the census (and some people are counted more than once) whereas the post-censal estimates are adjusted for "net under-coverage" and are presumed to count 100 percent of the population.* In the 2001 census data, the population for the GGH is estimated at 7.53 million; in the 2001 inter-censal estimates, the population is 4.6 percent larger, or 7.88 million.
- The annual number of births is estimated by applying fertility rates to the estimates of the female population (by age group) at the start of each year. The rates used were the 2001 fertility rates for Ontario, as estimated by Statistics Canada. For each Census Division, the division of the births between males and females is based on the actual male-female shares of the newborn population in the Census Division as of 2001.
- Each year, as the population ages by one year, each age group is moved up to the next bracket. In the process, "survival rates" (the percentage of people in each age-sex group who are still alive one year later) are applied, to account for deaths. Survival rates are derived from Statistics Canada data for Ontario as of 1995-1997.
- Adjustments are made for migration -- adding the projected number of immigrants, subtracting the projected number of emigrants, and adding (or subtracting) net interprovincial and net intraprovincial migration. In Section 3 of this report, a method was developed for projecting each of these components of migration, and a summary table showed factors for each of the components, for three aggregated areas: the Inner Ring, Outer Ring, and GGH. In developing the following projections, the sets of factors were projected individually for each of the 16 Census Divisions in the study area. The migration components have been measured and projected in the following way:
- Immigration is the percentage of Canada's immigrants who move into the Census Division each year. The Hemson report (page 20) assumes that immigration to Canada will average 218,000 people per year during 2001 to 2006, and just under 210,000 for the remainder of the projection period. The same assumptions are used here. After total migration is estimated for each Census Division, the migrants are distributed by age and sex using the actual distribution (for the respective Census Divisions) for immigrants who arrived from 2001 to 2003. The assumption that the level of immigration will be stable for a 25-year period is quite strong. For example, in fall 2005, the federal government started to argue for increased immigration targets. It has been suggested that annual immigration could be as high as one percent of Canada's population, which would result in annual figures of more than 300,000.
- Emigration is expressed as a percentage: the number of net emigrants from the Census Division divided by its population at the start of the year. Given the lack of data for analysis, it has been assumed that for each Census Division, the rate is equal to the average seen over the 1997-to-2004 period. The age-sex distribution is based on the actual distribution (for the respective Census Divisions) of emigrants from 2001 to 2003.
- Net interprovincial migration is expressed as a percentage: net interprovincial migration to or from the Census Division, divided by the population of Canada excluding Ontario at the start of the year. Long-term population projections are needed for Ontario and Canada. The projections used here are from Statistics Canada, "Projection 2: medium-growth and medium inter-provincial." These projections cover the 2001-to-2026 period. The projections have been extended to 2031 in this analysis. In applying the projections of net migration, the age-sex distribution is based on the actual distribution (for the respective Census Divisions) of interprovincial in-migrants in 2001-2003.
- Net intraprovincial migration is expressed as a percentage: net intraprovincial migration to (or from) the Census Division divided by the population of Ontario at the start of the year. The age-sex distribution is based on the actual distribution (for the respective Census Divisions) of net intraprovincial in-migrants in 2001-2002.
- This process was followed for each year of the 2001-to-2031 projection -period.
Using population estimates adjusted for "net under-coverage," the population of the GGH is assumed to be about 7.88 million in 2001. For 2031, the projections indicate a total population of 10.48 million, an increase of 2.60 million (33.0 percent) over 30 years. Over the 30-year period, these projections indicate average annual growth of 86,700 people per year (1.0 percent per year). The rate of population growth is projected to decelerate rapidly over the period:
- From 2001 to 2011, population growth averages 109,600 people per year (1.3 percent).
- From 2011 to 2021, the growth rate is reduced to 88,600 people per year (0.9 percent).
- From 2021 to 2031, the growth rate is 62,000 people per year (0.6 percent).
Table 11 summarizes the components of population growth for the Inner Ring, the Outer Ring, and the GGH.
- Slight increases in the number of births provide increasing contributions to growth for all three of the areas.
- Mortality rises sharply (the consequence of an increasingly older population), tripling the annual number of deaths in the GGH.
- Immigration falls slightly during the period.
- Emigration increases slightly.
- Interprovincial net migration is an increasingly negative factor over the 30-year period. This change is due to the lower employment rate in the GGH and increased housing costs. It can be further interpreted as the consequence of the aging population and the increased rate of retirements over the 30-year period. Since some retirees leave Ontario to return to their original homes or to move to areas with a lower cost of living or a more congenial climate, the aging of the population helps drive increased out-migration to other provinces.
- Intraprovincial net migration will deteriorate slightly during the 30 years, again, partly as the consequence of departures by retirees.
- Overall, the primary cause of the slowdown in population growth is the anticipated increase in mortality.
Table 11: Components of Annual Population Growth in the Greater Golden Horseshoe
Source: Will Dunning Inc.
Over the 30 years, the projections indicate a shift in the shares of population and population growth:
- In 2001, the Inner Ring had about 74.1 percent of the GGH population, and the Outer Ring had about 25.9 percent.
- During 2001-2011, the Inner Ring receives 69.6 percent of the GGH's population growth. In 2011-2021, the Inner Ring's share of growth falls to 65.7 percent. During 2021-2031, the Inner Ring share of growth falls again to 61.2 percent. Over the entire period, the Inner Ring is projected to receive 66.3 percent of the GGH population growth and the Outer Ring 33.7 percent.
- By 2031, the Inner Ring's share of the GGH population is projected to be 72.1 percent, versus 74.1 percent in 2001.
Table 12: Actual and Projected Population by Area, 2001 to 2031
Share of GGH Growth
Source: Will Dunning Inc.
As we have seen, economic cycles affect rates of population growth, through variations in the components of migration. These projections of population growth for 2001 to 2031 incorporate those findings. Under neutral assumptions for economic prospects, changes in migration tend to reduce population growth in the Greater Golden Horseshoe. However, the changes in migration are expected to be relatively minor. More fundamentally, the aging of the population, and the consequent expected increase in mortality, is expected to be the primary factor resulting in slower population growth in the GGH.
The next two sections further analyze the implications of population growth, by generating estimates of housing demand and employment growth. These two factors are the major drivers of land requirements for the study areas.
* The projections performed by Hemson in its Growth Outlook for the Greater Golden Horseshoe used the census data and a similar cohort-survival model. At the end of the exercise, the Hemson model added an adjustment for under-coverage. In all likelihood, the Hemson approach would generate results similar to those developed in this report, if similar assumptions were used for the key input variables.