Projecting the population

Today, a new set of population projections were released by Statistics Canada.

They tell a story about what the population of Canada, the provinces and territories might be in 2038, as well as Canada’s projected population in 2063.

Statistics Canada has been producing population projections since the mid-1970s. Updates are done about every five years, following the rebasing of the population estimates data with the last census available. The population estimates on July 1, 2013, form the basis of the projections released today.

For this set of projections, the agency has created seven scenarios with different combinations of plausible assumptions about future developments in fertility, mortality, immigration, emigration and interprovincial migration. The scenarios provide high-, medium- and low-growth projections that reflect the variability involved in creating projections.

Projection results show that under the medium-growth scenario, the population of Canada could reach 51.0 million people by 2063. In all scenarios, migratory increase would be the main driver of population growth at the national level, continuing a pattern that began in the early 1990s. Also in all scenarios, Canada’s demographic dependency ratio (the number of persons aged 14 years and younger or 65 years and older per 100 persons aged 15 to 64 years) would increase from 45.9 in 2013 to between 69.7 and 71.6 in 2063 depending on the scenario.

Not predictions

Patrice Dion, manager of the population projections for Canada, the provinces and territories, reminds people that these are not predictions. “Projections are not predictions. Statistics Canada is by no means trying to predict what will happen in the provinces and territories. Nobody knows precisely what the size of the population or the age structure across the provinces will be.”

A projection uses current data to estimate what might happen in the future, based on various assumptions and scenarios. A prediction is more like a forecast, with a high degree of confidence in the specific outcome.

Mr. Dion adds that some components of the projections are more variable than others. Births and deaths in Canada are relatively easy to project because trends have remained fairly consistent over time, at least in the recent decades. International migration has known important shifts in the past, but it has also remained fairly stable at about 250,000 immigrants per year in the past 20 years.

Bigger shifts tend to occur in projecting interprovincial migration, where the flow of people from one province or territory to another can change substantially in a fairly short time. For instance, after almost 30 years of interprovincial migration losses, Saskatchewan has recently experienced gains in that area.

Using projections

Governments, non-governmental organizations and the private sector use these projections to assess the potential population size and structure in the future. This helps them determine how to meet future needs. For instance, if a municipality wants to know whether to plan for elementary schools or seniors’ residences, it is useful to know the projected population growth and age structure.

Planners are also interested in the age distribution between sexes. Currently, women are still outliving men, but the longevity gap between them has been closing. This is an important trend because as people age, their prime support is generally a partner. If a couple’s life spans are similar, they may put fewer demands on social services. Therefore, home care services may be less necessary if a couple can live independently and support one another longer.

Projections are also useful to understand the long-term consequences of current regional differences related to demography, to better plan for the specific needs of these populations. For example, projections show that the challenges could be very different in Alberta, where strong population growth could continue, as compared with the Atlantic provinces, where population aging is more predominant.

Over the last few years, Statistics Canada has also disseminated other projection products using Demosim, its microsimulation model. This model permits the production of more detailed projections for subpopulations, such as Aboriginal or visible minority groups, and at more detailed levels of geography, including the census metropolitan area level. Following the rebasing of Demosim with the 2011 National Household Survey, new microsimulation projection products are slated for release beginning in 2015.

Checking accuracy

Since Statistics Canada has been producing projections for 40 years, it has had the opportunity to compare its projected growth to the actual population growth every five years.

“Obviously, the further you look in the future, the more discrepancy you could get with population projections,” Mr. Dion notes. “Because we update projections every five years, they change regularly based on the most current counts.”

“A good population projection is not defined by whether or not it matches reality. It is defined by whether it was plausible and useful to policy-makers at the time the projection was created,” says Mr. Dion. “More specifically, a good projection helps focus attention on potential events, risks and socioeconomic opportunities. A good population projection serves as a basis for developing reasonable expectations about the future, and for policy-makers to plan accordingly.”

For this new projection exercise, new methods were introduced to the projection methodology as part of an ongoing process to improve its quality. One such method related to the way interprovincial migration is projected. Another was the creation of an expert-based survey to get feedback from various stakeholder groups across Canada on future trends regarding the various components of population growth, such as fertility, mortality or international migration. In addition, the Demography Division at Statistics Canada has documented its methodology in a separate publication to help users understand the methods, assumptions and results of its demographic projections.