Data quality, concepts and methodology

Glossary

Aging (of a population): An increase in the percentage that seniors represent in the total population.

Baby boom period: The period following World War II, 1946-1965, marked by an important increase in fertility rates and in the absolute number of births.

Base population: The population at the beginning of a period used as a starting point for the projection exercise. A base population can be either a population estimate or the enumerated population from the Census.

Census coverage:

• Net undercoverage: Difference between undercoverage and overcoverage.
• Overcoverage: Number of persons who should not have been counted in the census or who were counted more than once.
• Undercoverage: Number of persons not enumerated in a census (who were intended to have been enumerated).

Demographic dependency ratio: The ratio of the population outside the working-age population, i.e. persons under 15 or 65 years and over to the working-age population (15 to 64 years).

International migration:  Movements between Canada and other countries that result by a change of permanent residence.

• Immigrant: Person who have been permitted by immigration authorities to live in Canada permanently.
• Emigrant: Person who leave Canada to settle in another country.
• Persons temporarily abroad:Those persons regroup Canadian citizens and landed immigrants living temporarily abroad who have not maintained a usual place of residence in Canada.
• Returning emigrants: Returning emigrants are Canadians citizens or landed immigrants who have emigrated from the country and subsequently returned to Canada to re-establish a permanent residence.

Interprovincial migration: Movement from one province to another involving a permanent change in residence. A person who takes up residence in another province is an out-migrant with reference to the province of origin, and an in-migrant with reference to the province of destination.

Life expectancy: A statistical measure derived from the life table indicating the average number of years of life remaining for a person at a specific age, if that person would experience during his life the age-specific mortality rates observed a given year (e_o refers to life expectancy at birth).

Median age: The median age is an age “x”, such that exactly one half of the population is older than “x” and the other half is younger than “x”.

Mortality life table: A description of the extinction, age by age, of a hypothetical cohort according to the mortality observed a given year.

Natural increase: Excess of births over deaths. It can be positive or negative.

Net migration: Difference between immigration and emigration or in-migration and out-migration for a given area and period of time.

Non-permanent residents: Persons from another country who had an employment authorization, a student authorization, or a Minister’s permit, or who were refugees claimants, and family members living with them.

Population growth: A change, either positive or negative, in population size over a given period.

Population pyramid: A special type of bar chart that shows the distribution of a population by age and sex.

Rate: The frequency of demographic events (births, deaths, migrations, etc.) in a population in a specified time period. Rates tell how frequently an event is occurring. Crude rates are rates computed for an entire population. Specific rates are rates computed for a specific subgroup – usually the population at risk of having the event occurs. Thus, rates can be age-specific, sex-specific, etc.

Ratio: The relation of one population subgroup to another subgroup in the same population; that is, one subgroup divided by another.

Replacement level: Mean number of births per woman necessary to assure the long-term replacement of a population for a given mortality level. Currently, the replacement level in Canada is about 2.1 children per woman.

Sex ratio: Ratio of males to females in a given population. It is usually expressed as the number of males per 100 females.

Total fertility rate: The sum of single year age-specific fertility rates during a given year. It indicates the average number of children that a cohort of women would have if the current age-specific fertility rates prevail over their reproductive period.