Voter turnout in the 2021 Canadian election was 62.25% according to Elections Canada, or 63% to be generous.
This is a decrease of 4 percentage points from the 67% turnout achieved in the prior 2019 election.
This voter turnout decrease coincides with a 38% increase in early voting.
The early voting vote-by-mail comes in two flavours: necessary and unnecessary.
The necessary vote-by-mail in the 2021 election was consistent with the 2019 election. There were about 50,000 out-of-town voters and 150,000 out-of-country voters who sent their ballots to Ottawa for counting.
The unnecessary vote-by-mail ballots were cast by in-town voters. These of course were justified by the pandemic for this election, but are unnecessary for future elections. These ballots were counted in each local riding, causing a delay of several days before the final results were confirmed.
The unnecessary vote-by-mail ballots totalled about 800,000 as reported in the media. I obtained this number from a Finn News report.
The increase is early voting also came from a huge increase in voting at the four days of advance polls. There were 5.78 million advance ballots according to a CTV report.
Combining the 800K in-town vote-by-mail ballots with the 5.78M advance ballots produces an early voting total of 6.6M ballots.
That's an increase of 1.8M early votes over the 4.8M cast in the 2019 election. A 38% increase.
Back in the day in the 1988 election when most ballots were cast on Election Day the turnout was 75%. It was hoped that making the voting process easier and more convenient would increase turnout. In the 10 elections since, that hope has been dashed by lower turnout rates.
Leaving the conclusion that early voting depresses voter turnout.
The above numbers are shown on the graph below.