The Liberals’ win of the 2015 election means that Canada will see a debate over electoral reform take place over the next 18 months. During the election the Liberals promised that the 2016 election would be the last to take place under Canada’s current first past the post system, and they have now committed to carrying out electoral reform without a referendum. One of the systems under considerations is an alternative vote (also known as a preferential ballot) system. Under a such a system the ridings that exist under first past the post would remain, but candidates would have to win at least 50% of the vote in order to be elected (under the current system candidates only need to win more votes than their closest competitor). Rather than voting for a single candidate voters would rank order candidates. When votes are counted, the last place candidate in a riding is eliminated and anyone who voted for her has their vote redistributed to their second choice candidate. If no candidate has 50% at that point the second last place candidate is eliminated and her votes are redistributed. This continues until a candidate has over 50%.
There are several reasons why individuals my favour electoral reform. Many are frustrated by the ability of parties to win majority governments with less than a majority of the popular vote. The last three majority governments were elected with 39.5%, 39.6%, and 40.9% of the vote. There is also concern that large numbers of votes have no impact the outcome of elections. Votes for 3rd and 4th place candidates, and votes for candidates that win well over 50% of the vote do little to change which candidate or party wins an election. There are also concerns that even the candidates elected to represent particular ridings are not fair representatives because many candidates win in ridings where more than half of the population voted for a different candidates. Many of these concerns speak to the way that first past the post skews the results of elections by either creating artificial majorities or underepresenting weaker parties. In this post I look at whether an alternative vote system would have been likely to change the results of the 2011 and 2015 elections. I find that it is unlikely that the results of either election would have been all that different under an alternative vote system. A change to alternative vote would ensure that Members of Parliament would have the support of at least 50% of the population, but do little to change the extent to which parties with less than majority support across the country win majority governments.
In looking at how the 2011 and 2015 elections might have unfolded under alternative vote I use a rather crude method that is based on the results of each election. I first separate out two types of ridings, one in which the winning candidate won at least 50% of the vote and one group in which the winning candidate won at least 45% of the vote. These ridings are unlikely to change hands under an alternative vote system. In the case of the ridings where the top candidate win at least 50%, there would be no need for eliminating last place candidates and redistributing votes. For the candidates with at least 45% of the vote, it is likely they will win enough second place votes from eliminated candidates to put them over the 50% threshold. They need to pick up just 5% (often times less) of the total vote from candidates finishing 3rd or lower. I count both of these groups of ridings as wins for the party that won them under the first past the post system. The remaining ridings, competitive ridings, are ridings that are reasonably likely to change parties under an alternative vote system. For these ridings I look at which parties are competitive in each riding to gain an idea of how much each party could add to the totals they have from the first two groups of ridings. A party is considered competitive in one of these ridings if it finishes first or second, or if it is the third place party and the gap between the 2nd and 3rd place parties is less than the number of votes won by 4th and 5th place parties. All numbers discussed in this post are percentages of total ridings. I use percentages because the number of ridings in the 2015 election was higher than the number of ridings on the 2011 election. All data used in this post comes from Pundits’ Guide.
It should be noted that a drawback of using past results is that campaign tactics and voters’ strategies are likely to be different under different electoral systems. Voters who strategically voted Liberal in 2015, for example, might have ranked NDP candidates first if they were voting in an alternative vote system. For this reason, the numbers in this post should not be taken as exact estimates of what would happened had the 2011 and 2015 elections been run under an alternative vote system. They do provide some idea, though, of what would have happened. It is also unlikely that changes in the voting system would have made a huge difference to electoral outcomes. There is still some incentive to strategic vote in alternative vote systems because the party with the most seats ends up being the one to form government. NDP supporters, for example, might end up voting Liberal to ensure that the Liberals have more seats than the Conservatives, and as a result, keep the Conservatives out of government.
A look at the seats that a party would have locked up even before the competitive seats are taken into account shows the Conservatives in 2011 and the Liberals in 2015 with a large lead in seats. In 2011 the Conservatives had 50% or more of the vote in 35.7% of ridings and 45% or more in an additional 9.4% of ridings. This means that the Conservatives would need to win only an additional 5% from the remaining competitive ridings in order to retain their majority government. In 2015 the Liberals do not do quite as well, but they still win a large number of seats before the competitive seats are taken into account. In 2015 they won 27.2% of seats with at least 50% of the vote, and an additional 13.9% with at least 45% of the vote. This gives the Liberals 41.1% of seats. They need just 9% from the remaining competitive ridings in order to hold on to their majority.
Also noteworthy is the small number of safe seats that each of the third parties would have won in an alternative vote system. In 2011 the Liberals had 45% or more in just 2.3% of seats while in 2015 the NDP had 45% or more in just 2.1% of seats. By comparison the NDP in 2011 had 45% or more in 21.1% of seats while the Conservatives in 2015 had 45% or more in 20.1% of seats. The Greens have just one safe seat (Elizabeth May’s) in both years and the Bloc Quebecois have no safe seats in either 2011 or 2015. For one of the third or fourth parties to catch the second place party and become the official opposition they would have to win a large number of the competitive seats. Unless there is a large swing in competitive seats, it is unlikely that either governing party or official opposition in 2011 or 2015 would have changed under an alternative vote system.
A look at the ridings in which parties are competitive shows not much difference between the three largest parties in 2011 and that the Liberals and NDP are competitive in most ridings in 2015. In 2011 each major federal party was competitive in around 20% of ridings. The Conservatives would have needed to win only 23.4% of the ridings in which they were competitive in order to win a majority government. Further, neither the NDP nor the Liberals are competitive in enough ridings to be able to catch the Conservatives and form government. The NDP can win a maximum of 40.9% of seats in 2011 while the Liberals can win a maximum of 24.4% of seats. Neither can exceed the 45.1% of safe seats that the Conservatives had in 2011. Finally, the Liberals would need to win nearly all of their competitive seats and have the NDP win few to none of the seats they are competitive in just to become the official opposition.
In 2015 the Liberals need to win just 27.4% of the seats they are competitive in to retain their majority. The best the Conservatives can do based on the number of seats they are competitive in is 39% while the NDP can win a maximum of 30.2% of seats. Neither could catch the Liberals even if they won none of the seats in which they were competitive in. The NDP could replace the Conservatives as official opposition, but they would need to win an overwhelming number of the seats that they are competitive in while the Conservatives would have to win few of the seats they are in competitive in. Given the discrepancy in safe seats, it is unlikely that the NDP would end up as official opposition if the elections were run using an alternative vote system. In both 2011 and 2015 the opposition and 3rd are not competitive in enough ridings in order to have a strong likelihood of changing the government. In contrast, the relatively small proportion of seats that each governing party would need to win to gain a majority makes such an outcome reasonably likely.
The kinds of ridings that are most likely to be competitive are likely to favour the Liberals. At a centrist party, the Liberals do best in races that are either Conservative-Liberal races or Liberal-NDP races. In the Conservative-Liberal races the Liberals are likely to pick up the 2nd choice votes of New Democrats, while in Liberal-NDP races the Liberals are likely to pick up the second choice votes of Conservatives. In both 2011 and 2015 this suggests that the Liberals will pick up a substantial number of competitive seats. In 2011 15% of seats are either Conservative-Liberal or Liberal-NDP races while in 2015 13% of races are either Conservative-Liberal or Liberal-NDP races. This combined with the likelihood that they will pick up at least some of the other seats suggests that they would get the additional 9% of seats they need in 2015 to hold on to their majority government. The Conservatives might have a slightly more difficult time holding on to their majority in 2011, but the small number of seats that they need makes them likely to do so. There were likely enough Conservative-NDP races and NDP and Green voters that would rank the Conservatives 2nd for the Conservatives to win the additional 5% of seats they need to hold on to their majority in 2011.
Unless alternative vote led to a dramatic change in the way that voters act, the adoption of such a system would have done little to change the results of the 2011 and 2015 elections. It would not have prevented parties that had less than 50% of the popular vote from winning majority governments, nor would it have increased the representation of weaker parties that have difficulty winning seats under first past the post. There are too many ridings in which one party won at least 45% of the vote for alternative vote to have made a substantial difference to the outcome of the 2011 or 2015 elections. A change to a proportional system such as single transferable vote or to mixed member proportional would be needed in order to create such a change in outcomes.