Voting strategically: Is it worth it?

By the time polls close in the Oct. 19 Canadian federal election, roughly 15 million Canadians will have cast their ballots to elect 338 members of the House of Commons, an average of nearly 45,000 votes per constituency. During the campaign, there have been suggestions from time to time that voters in certain constituencies should “vote strategically”, usually with the goal of blocking the Conservative candidate from winning, though nothing stops what would otherwise be a Conservative voter from casting their own strategic vote in an attempt to block a New Democrat, Liberal, Bloquiste or Green from being elected.

This might be no problem if a candidate you genuinely like has been endorsed. But what if you find yourself leaning toward a third candidate — either as a candidate you really would like to see elected, or as the best of a bad lot — but worry that your least-preferred candidate might win if you don’t vote for a compromise candidate?

Put yourself in the position of a voter in the completely fictional riding of Waskaiowaka Centre. This voter logs on to her Twitter account one day, and finds out that a poll of 400 voters in the constituency shows a dead heat:

Big Party #1 — 35%

Big Party #2 — 35%

Medium Party — 26%

Minor Party — 3%

Fringe Party — 1%

Our voter doesn’t care much for the two big parties, and has been so far leaning toward the Minor Party because it has some interesting ideas and hasn’t been in her face as much as the other parties. But she particularly dislikes Big Party #1, the incumbent Member of Parliament’s party, and wants to see it lose the parliamentary seat.

So, she considers putting aside her doubts, holding her nose as it were, and voting for Big Party #2.

Is it worth it?

Using a spreadsheet, I generated 1,000 possible random scenarios based on the percentages given above, allowing for a bit of random deviation of up to a few percentage points to either side.

Big Party #1 wins between 13,400 and 18,529 votes (average: 16,031), and wins the seat in 527 of the 1,000 scenarios.

Big Party #2 wins between 13,391 and 18,520 votes (average: 15,940), and wins the seat in 473 of the 1,000 scenarios.

The Medium Party wins between 9,945 and 13,764 votes (average: 11,798).

The Minor Party wins between 1,148 and 1,588 votes (average: 1,363).

The Fringe Party wins between 383 and 529 votes (average: 454).

The winning party’s margin of victory ranges from 1 vote to 4,993 votes.

If one sets the threshold for one’s vote as having made a significant positive or negative difference if the margin of victory is 100 votes or less, that occurred in just 36 of the 1,000 scenarios, or just 3.6 percent of the time.

If one sets the threshold for one’s vote as having significantly affected the outcome at the margin of victory being 20 votes or less, that outcome occurred in just 10 of the 1,000 scenarios, or just one percent of the time, despite the close race in Waskaiowaka Centre.

It is up to each voter to make his or her own decision. The case for voting strategically is clearly a compelling one for some voters, given the amount of organization that has gone into strategic voting efforts during the 2015 Canadian election campaign. But if you are wrestling with whether to vote strategically or with your conscience, the odds of your vote being equivalent to one percent or even five percent of the victor’s margin in even a tight race are small enough that you need not fear voting with your conscience.

That we’ve come to all this suggests that, no matter who forms the government after next week’s election, it’s time to give Canadians a free and equal choice between first-past-the-post, the various forms of proportional representation and instant-runoff voting.

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About theviewfromseven
A lone wolf and a bit of a contrarian who sometimes has something to share.

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