Voting system affects outcome, simulation finds

A simulated election that examined different voting methods during last week's Ontario election shows that for at least some voters, how they cast their ballot depends on the voting system presented to them.

A simulated election that examined different voting methods during last week's Ontario election shows that for at least some voters, how they cast their ballot depends on the voting system presented to them.

Entitled Three Ontario Votes, the project allowed voters to cast fictional ballots online ahead of the Oct. 6 Ontario election using three different electoral systems. More than 9,000 people visited the site since its launch on Sept. 17.

The intention of the project was to inform voters about the differences of the three systems studied: first-past-the-post (FPTP), alternative vote (AV) and proportional representation.

Canadian elections use the first-past-the-post electoral system, but is it the best one? ((CBC))

See the table at the bottom of this story for an explanation of how each of the three different voting systems work. The FPTP system is the one currently in use in all provincial and federal elections in Canada.

Using the online tool, visitors to the site were asked to vote three times, using each of the three voting systems. They cast their anonymous votes using a list of real candidates in their riding.

The researchers and academics behind Three Ontario Votes published the results of data collected during the study and also calculated how the actual results from last week’s election would be different in each of the voting systems studied.

First, the study examined how site visitors cast their ballots in each of the three systems.

Votes cast under three different electoral systems

  FPTP AV (Share of first-place votes) PR
Liberal 47.5% 41.2% 39.4%
PC 10.5% 10.4% 8.8%
NDP 32.4% 34.4% 34.8%
Green 8.2 % 11.7% 12.1%
Other 1.5% 2.4% 5.0%

Those who conducted the study concede the results in the graph above are not representative of the actual election results.

Most participants kept their choices consistent regardless of the voting system they were using. However, many switched their votes when using different systems. For example, 12 per cent of voters ranked a different party as their top choice in the AV system than the one they voted for in the  FPTP election. A total of 18 per cent supported a different party under the PR system than they did when voting under an FPTP system.

Laura Stephenson, a professor at the University of Western Ontario and one of the researchers behind Three Ontario Votes, said the results show that voters are aware of how their votes would be translated in each of the different systems.

"It shows that incentives exist in each voting system and that people are aware of them and respond to them," she said.

Translating actual results from the Oct. 6 election shows how the AV system would shift a few percentage points of support from the Liberal and Progressive Conservative parties to the NDP and Green Parties (see table below). A PR system would also benefit the NDP, Green Party and fringe parties at the expense of the Liberal and PC parties, but the results are even more drastic.

Actual FPTP Election Outcome and Weighted AV and PR Vote Results

FPTP (Actual election outcome) AV (first preferences) PR
Liberal 37.6 % 33.6% 32.1%
PC 35.4% 32.7% 28.4%
NDP 22.7 24.6 26.2
Green 2.9% 6.5% 7.2%
Other 1.3% 2.6% 6.2%

One aspect of the AV system that sets it apart from other methods of voting is the option for voters to rank parties second or third after their first choice. A total of 67 per cent of those who ranked the Liberals as their first option ranked the NDP second. A total of 56 per cent of those who ranked the NDP first ranked the Liberals second.

Seat breakdowns vary widely from actual vote under PR

Perhaps most interesting is how a PR system would translate into seats. In last week’s provincial election under FPTP system, the Liberals came just one seat shy of a majority, winning 53 seats while the PCs finished with 37 seats, the NDP 17 and the Green Party with none.

Under a PR system, the Liberals would win only 36 seats while both the PCs and NDP would wind up with 31 seats each. The Green Party would fare much better if last week's election used the PR system. Instead of no seats, the Greens would come away with eight.

Actual FPTP seat distribution and estimated PR seat distribution

FPTP (actual election outcome) PR
Liberal 53 36
PC 37 31
NDP 17 31
Green 0 8
Other 0 1

Supporters of the PR system often argue that it results in governments that more accurately reflect voters’ intentions. A common argument against PR however is that it too often leads to minority governments.

Alternative voting  First-past-the-post Proportional representation 
Also known as preferential voting. Used in elections for the House of Representatives in Australia, where voting is compulsory.

Used in Canadian provincial and federal elections.

Used in elections for the House of Representatives in the Netherlands.

Voters rank the candidates according to their preference. Any candidate getting more than 50 per cent of the vote wins. If no candidate gets more than 50 per cent of the vote, the weakest candidate is eliminated. Voters cast a vote for a candidate associated with a party in their respective districts. The candidate with the most votes is the elected representative for that district. Parties send out lists of their candidates. Voters cast their ballots for the party. The proportion of seats the party gets is roughly equivalent to the number of votes cast for that party.
The people who cast their ballots for the eliminated candidates will have their votes allocated to the candidate they picked as their second choice. The process is repeated

A mechanism known as the d'Hondt formula is used to help allocate the seats.