Overview of the Census of Population
Chapter 1 – Introduction

General information

The census is Canada's largest and most comprehensive data source. The Census of Population collects demographic and linguistic information on every man, woman and child living in Canada. The Census of Agriculture, conducted the same month, collects information on Canada's agricultural operations.

The census is the main source of data available in a standardized format for small areas. It provides nationally comparable data that can be cross-classified to show details. It is also the main body of comprehensive statistical data at the subprovincial level on Canada's population.

Census of Population

The Census of Population is taken to meet statutory requirements. For example, population counts are used to realign the boundaries of federal electoral districts, to calculate transfer payments between levels of government, and to support a variety of programs.

The data are needed by both the public and private sectors to support decision-making in many areas. For example:

  • to plan community services such as schools, day care, police services and fire protection
  • to forecast consumer demand
  • to conduct market research studies.

More detailed information on how census data are used can be found in Chapter 10 – Dissemination.

Why is the census in May?

The first May census was held in 1996. Previous censuses were held in early June. However, the May date allows collection procedures to run more smoothly and therefore costs less. With a mid-May census, delivery of questionnaires and many of the follow-up procedures can be accomplished during the same month, thus avoiding the problem of people moving to a different address on May 1 or June 1. In addition, the mid-May date allows more time for final follow-up to be completed before the busy summer holiday period begins. The May data collection of the census has improved population coverage and the quality of Census data.

Census history

1666 – The first Canadian census was taken in New France by Intendant Jean Talon. The recorded population (excluding Aboriginal persons and royal troops) was 3,215. Information was obtained on age, sex, marital status and locality. In addition, the census identified professions and trades for 763 persons.

1666 to 1867 – Numerous censuses were taken at irregular intervals in the colonies of France and Britain that became parts of Canada.

1867The Constitution Act, 1867 (formerly the British North America Act) included the requirement that a census be taken every 10 years (decennially) in order to determine representation by population in the new Parliament.

1871 – The first decennial census was taken in this year. The census enumerated the population of the four original provinces (Nova Scotia, New Brunswick, Quebec and Ontario). Manitoba and British Columbia, which had also joined Confederation, were surveyed separately.

The 1871 Census was the first to use the de jure method of enumeration rather than the de facto method used in Europe both then and now. The de facto method enumerates people where they are found on Census Day. The de jure method enumerates people according to their usual place of residence.

1896 – A mid-decade census was held in Manitoba beginning in 1896 and then in Saskatchewan and Alberta beginning in 1906. These censuses were needed to measure the rapid growth taking place in the West.

1905 – The census office became a permanent bureau of the federal government.

1912 – Responsibility for conducting the census was transferred from the Department of Agriculture to the Department of Trade and Commerce.

1918 – The Dominion Bureau of Statistics was created.

1941 – Sample information was collected for the first time. One in 10 households were asked an additional 27 questions about their dwelling (type, number of rooms, cooking fuel used, etc.).

1956 – A quinquennial Census of Population and Agriculture was held in all provinces across the country, replacing the mid-decade censuses of the Prairie provinces. The results of this census indicated a dramatic increase in the number of people moving to the cities, a rapid growth in the birth rate, and high levels of immigration.

1971 – Under the Statistics Act of 1971, the Dominion Bureau of Statistics was renamed Statistics Canada. The Act also confirmed that a Census of Population and a Census of Agriculture shall be taken every five years (quinquennially).

In 1971, self-enumeration was first introduced. With the exception of Indian reserves and remote areas, census forms and completion instructions were dropped off at private homes and respondents were asked to complete their own questionnaires. In urban areas with a population of 10,000 or more, respondents were asked to mail their completed questionnaires back in a pre-addressed envelope. In rural areas or smaller urban centres (with a population of less than 10,000), respondents were asked to keep their questionnaires until a census interviewer came to pick them up.

1991 – All respondents in self-enumeration areas (over 98% of the population) were asked to return their completed census forms by mail. The return rate was 85%, with more than 27 million people in over 10 million households counted. Information on common-law partners was also collected for the first time.

2001 – For the first time, data were collected on same-sex couples.

2006 – In the 2006 Census, forms were delivered by Canada Post to about 70% of households. The remaining 30% received the form from an interviewer as in previous censuses. For the first time, all Canadians could answer the census questionnaire online. This was also the first time people were asked if they wanted to have their personal information released in 92 years for the purpose of genealogical research. Respondents were also asked whether they would give Statistics Canada permission to access their tax files. This permission was sought in an effort to reduce response burden.

2011 – The positive response to the online option (18.5%) in 2006 prompted a major change in the methodology for the 2011 Census. Starting May 3, a letter was delivered to 60% of Canadian dwellings. This letter replaced the traditional paper questionnaire and provided information so respondents could complete the questionnaire online. The letter also contained a toll-free number respondents could call to request a paper questionnaire. Questionnaire packages were delivered to about 20% of dwellings by mail. The remaining 20% of dwellings had questionnaires dropped off by enumerators. At a small number of dwellings, enumerators conducted personal interviews.

All questionnaires explained to respondents how they could complete the census online. Questionnaires completed online require fewer edits, do not require scanning and data capture, and usually result in a higher overall item response rate.

For 2011, Statistics Canada did not use a mandatory long-form questionnaire as part of the census. Information previously collected by the mandatory long-form census questionnaire was collected as part of the new voluntary National Household Survey (NHS).

Collection of the NHS began within four weeks of the May 2011 Census. Approximately 4.5 million households received the NHS questionnaire.

The 2011 Census questionnaire consisted of the same eight questions that appeared on the 2006 Census short-form questionnaire, with the addition of two questions on language.

Privacy and confidentiality

Statistics Canada recognizes the importance of maintaining the confidentiality of personal information and has made the protection of such information its highest priority. Confidential data never leave Statistics Canada premises, nor are they ever out of Statistics Canada's control.

Providing personal information to anyone, whether in a census, survey, or in any other manner, does involve some loss of privacy. However, it is recognized that the public benefits of accurate data far outweigh this minimal loss of privacy, especially when measures are taken to ensure that personal information is kept strictly confidential.

Developing census questions

Statistics Canada takes care to ask questions that are in the public interest and that provide information that is not available from other sources. All questions have been carefully tested and the results show that respondents are willing to answer them. The Agency has paid full attention to the protection of personal information outlined in the Charter of Rights and Freedoms and the Statistics Act. Judicial rulings on this issue have held that census questions do not contravene the Charter.

Personal information

Statistics Canada does not release personal information without the consent of the individual. Census information is only seen, on a need-to-know basis, by employees of Statistics Canada or persons sworn under the Statistics Act.

Consent to release personal information

The 2011 Census asked respondents if they would consent to having their personal census information released to Library and Archives Canada in 92 years (Question 10 on the census questionnaire).

Oath of secrecy

All Statistics Canada employees, including interviewers, are sworn to secrecy under the Statistics Act. This oath remains in effect not only during employment, but for the rest of their lives. Penalties for divulging personal information include:

  • a fine of up to $1,000
  • imprisonment for up to six months
  • both a fine and imprisonment.

Published data

Statistics Canada is bound by law to protect the identity of individuals in all published data. All data releases are screened so that anonymity is assured; data are randomly rounded to a multiple of five or ten; and no detailed data are released for areas with populations below a certain size.

Names and addresses

Names, addresses and telephone numbers are used to make sure people have not been missed or counted twice (census coverage studies) and for follow-up (when incomplete information has been provided), or for selection in a small number of postcensal surveys.

Retention of census information

Until 2001, questionnaires were microfilmed and then destroyed after the census information was captured. The 2006 Census questionnaire responses have been stored electronically in flat file format. The 2011 Census responses will be stored the same way. Strict security precautions limit access to both the microfilms and stored records. Individuals can access their own census records for purposes such as obtaining proof of age for old age security.

Security online

The latest technologies were used to ensure that Statistics Canada's strict security and confidentiality requirements are met without imposing any pre-registration or lengthy download processes for the census Internet application.

Official languages

As early as 1871, census questionnaires were produced in English and French. This tradition became law in 1988 under the Official Languages Act. The Act states that English and French are the official languages of Canada and that service to the public must be provided in both languages.

As in previous censuses, procedures were in place for the 2011 Census to ensure that members of the public received service in the official language of their choice.