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Estimation of Voter Turnout by Age Group and Gender at the 2019 General Election

Appendix: Methodology

The purpose of this study is to estimate voter turnout rates for several different demographic groups of interest defined by age and sex at the national, provincial and territorial levels.

Definition of turnout

The official turnout results published by Canada's Chief Electoral Officer are calculated using the number of registered electors in the denominator instead of the size of the electoral population. However, the coverage of the electors list (that is, the percentage of eligible electors listed) changes over time, depending, among other things, on many factors related to list maintenance activities. If turnout is calculated relative to the number of electors on the list, then measures of change in turnout over time will be confounded by these other factors. This problem is exacerbated when turnout is broken down by age, since the changes in coverage over time may be quite different for different age groups. For example, an apparent decrease in youth turnout may be partly due to Elections Canada's efforts to increase coverage of youth on the list. For this study, turnout is defined as the number of ballots cast divided by the number of eligible electors. This denominator is calculated by adjusting population estimates obtained from Statistics Canada to include only citizens 18 years of age or over as of polling day (October 21, 2019). In order to get the numerator, we need to know how many people cast a ballot and what group they fall into. Ultimately, the numerator is obtained by adding this estimate to the known numbers of ballots cast by members of the different groups, whether at advance polls, by special ballot or by persons registering when they voted on polling day. Until 2015, a random sample of electors was used to produce an estimate of the numerator for each demographic group of interest. Since the 43rd general election, lists of voters are recorded on digital support at the end of election day, resulting in a faster, more accurate estimate of voter turnout for the entire country.

Electoral population

The size of the electoral population within a demographic group of interest is required for the denominator of the turnout estimates. This was based on Statistics Canada's 2016 Census, with adjustments made to remove non-citizens and those under 18 years of age, who are not eligible to vote, and to take into account population growth during the time elapsed between census day and polling day, using demographic information provided by Statistics Canada and Immigration, Refugees and Citizenship Canada. The electoral population estimates were also adjusted to account for the net number of citizens missed in the 2016 Census.

For the purposes of this study, age as of polling day was divided into eight groups, consistent with previous studies. These groups were defined as follows:

Age group Date of birth
From To
1st time* 20 October 1997 21 October 2001
not 1st time* 22 October 1994 19 October 1997
25–34 22 October 1984 21 October 1994
35–44 22 October 1974 21 October 1984
45–54 22 October 1964 21 October 1974
55–64 22 October 1954 21 October 1964
65–74 22 October 1944 21 October 1954
75+ 2 January 1900 21 October 1944

*Youth aged 18–24 were split into two groups: those who were eligible to vote for the first time in the 2019 general election (youth born between October 20, 1997, and October 21, 2001) and those who were eligible to vote in the 2015 general election (youth born between October 22, 1994, and October 19, 1997).

Data collection, processing and quality

Elections Canada maintains the National Register of Electors, a database of Canadians who are 18 years or older. The Register is regularly updated between and during elections, using data received directly from electors, administrative data received through agreements with federal, provincial, and territorial agencies, and data received from other sources, in accordance with the Canada Elections Act. This administrative data contains the address, date of birth and sex for everyone on the final voters list. They do not indicate which electors cast ballots, except in special circumstances. The administrative data from the elections, however, can be used to identify all those who voted at advance polls, by special ballot, or who registered to vote on polling day. For those who voted on polling day but were registered earlier, the information required was only available on the strike lists and sequence number (bingo) sheets used to administer the election.

Prior to the 2019 general election, a sample of polling divisions was used to retrieve strike lists and count the number of voters, since it would have been very difficult to collect all data in paper form. Changes to the Canada Elections Act under Bill C-76 required Elections Canada to prepare a compilation of all data of electors who voted and make them available to political parties and candidates in electronic format. As a consequence, during the 43rd general election, for the first time, voters' information was collected electronically and allowed Elections Canada to use a complete and consistent set of data to produce these estimates without having to resort to sampling, thus greatly improving the accuracy of the estimates.

In previous elections, because estimates were produced by means of a random sample, turnout rates were subject to sampling errors, and confidence intervals were calculated to show the accuracy of estimates and to measure sampling errors. Other errors can still exist that cannot be attributed to sampling variations. These are errors that can occur at the stage of data collection and processing. Data collection at Elections Canada relies on human input, be it an elector filling a form with his/her biographical information, or a worker entering the vote status on a spreadsheet. Even though Elections Canada has put in place procedures to minimize them, errors can still be found. Users should be aware of the types of errors that can occur, so they can assess the adequacy of the data for their own purposes.

Typical errors impacting the turnout analysis include:

  • Missing or erroneous voter information (sex, date of birth)
  • Missing or erroneous strike list information (misplaced sheets, data capture errors)
  • Errors introduced during imputation to replace missing or invalid data
  • Errors in estimating the electoral population

Estimation

In each polling division, the number of voters for each sex and age group is obtained by adding up the individual voters. The sum of the initial estimates gives the estimate at the electoral district level. The estimate at the provincial or territorial level is obtained by adding the estimates of the districts belonging to a given province or territory. Finally, the sum of the provincial and territorial estimates is used to determine the national estimate.

Voter counts are tallied from the Final List of Electors and the National Register of Electors; these contain the date of birth and sex of individual electors and are used when estimating voter turnout by age and sex. The Final List of Electors and the National Register of Electors collect data from different sources:

  • advance voters are collected by poll workers at the poll site. These data are then digitized and early voters are struck from electoral lists come election day, to avoid double voting;
  • special voters (incarcerated voters, international voters, voters in the Canadian Armed Forces, and mail-in ballots) are collected at the offices of returning officers or other Elections Canada service points; these voters are struck from the list to avoid double voting;
  • polling day registrations and sequence numbers of electors who voted on election day were manually recorded on forms by poll workers in each polling station; these forms were sent to the returning office for data capture in each of the 338 returning offices and the data transferred onto the Final List of Electors.

There is no fully automated and digitized procedure to collect data; all data sources require one or more manual data entry processes. Data entry and data capture errors, misplaced or missing documents, however rare, do exist. Therefore, estimates of the number of voters computed from the Final List of Electors and the National Register of Electors are not entirely consistent in general with the totals derived from the official voting results. Voter estimates are thus adjusted to the official voting results, broken down by age and sex group, and the results are divided by the corresponding group of the electoral population to determine voter turnout by age and sex.