Is there any truth to the claim that preferential voting would result in more majority governments for centrist parties? The evidence seems to point to the opposite conclusion, fewer majority governments and no benefit to centrist parties. Both in Australia with Alternative Voting, and in France with two-round voting, two forms of preferential voting, centrist parties have not been successful.
The history of preferential voting is full of karmic surprises. Alternative voting was introduced in Australia by the Nationalist Party, some say to counter the rising Country Party that was “taking” its votes and causing it to lose seats to the Labour Party. It was thought with the new voting system that the Country Party would be eliminated and that the second choice of its candidates’ voters would go to the Nationalists. In fact Nationalists lost a third of their seats to the Country Party and were forced into a coalition with the Country Party, whose terms included the resignation of their leader. Both parties still exist a hundred years later, under different names, and the coalition of the two often alternates in power with the Labour Party. Centrist parties have sprung up over the years but they are never very successful. The country has minority, majority, and coalition governments, and many independents have been elected in every election since 1990.
A similar story emerges in Canadian provinces of BC, Alberta, and Manitoba, who introduced alternative voting in the hopes of reducing the influence of the CCF or the Social Credit party. This usually backfired for the governing party that introduced it but led to stable, less adversarial governments, often featuring the parties whose seats they intended to diminish. Whether the system is FPTP or Preferential Voting, voters tend to get what they want but Preferential Voting gives it to them with less distortion.
Fifteen years ago, would the Reform Party and the Progressive Conservatives have done as poorly because vote splitting if Canada had used Preferential Voting? It depends on whether vote splitting was mitigated by strategic voting or benefited others, on whether Reform and PC candidates would have been each other’s second choice for their voters and on whether voting behaviour would have changed, but one thing is certain: exploiting divisions between similar parties could not have worked.
Other effects of preferential voting in Australia are interesting. Like-minded parties with distinct values are not forced to merge for survival, since they do not interfere with each other’s chances. It is safe to vote for candidates of small parties; it is not a wasted vote nor one that helps someone you do not like, so they have a fair chance at being elected. If they get too few votes, the voters that supported them are sought after for their second-choice votes, so much so that major parties incorporate some of the policies of the smaller parties in order to attract their second choice votes. That gives those voters more direct influence on achieving their goals, without relying on backroom deals between politicians.
The other interesting effect is the rise of independent elected MPs. Australia has elected an average of 4 cross-bench (neither government nor opposition) independents per election in the last 25 years. They are usually elected with second and third choice votes, and get a consensus that none of the major party candidates can achieve.
So who benefits most? There is no pattern of left or right or centre, it is whoever can put aside divisiveness and reach out to voters for whom they are not the first choice, and if major parties don’t do it, then minor parties and independents will.