Preferential voting

Preferential systems of voting deal with the problem of winning candidates not necessarily winning a majority of votes by making voters indicate a series of preferences among the candidates. Voters write ‘1’ in a box on the ballot paper next to the candidate they want to see elected, then ‘2’ against the candidate they would prefer after their first choice, and so on. In the case of Melbourne, voters would have to indicate seven preferences by numbering the boxes on the ballot paper 1, 2, 3, 4, 5, 6 and 7.

Counting the votes

Where no candidate wins more than 50 per cent of the first preference votes, the least popular candidate (the one with the fewest first preferences votes) is eliminated. The second preferences of voters who voted for that candidate are then distributed among the remaining candidates. If there is still no candidate with a majority of votes, the remaining candidate with the fewest votes is eliminated and the preferences of his or her voters distributed. This process is repeated until one candidate gets more than 50 per cent of the votes.

In Melbourne in 2010, no candidate won a majority of first preference votes. The Democrat candidate, with fewest votes, was eliminated and his preferences distributed (see table). No candidate had a majority of votes after this process. The Socialist candidate was then eliminated, followed by the Family First candidate and the Sex Party candidate. Labor’s Cath Bowtell still had more votes than the other two remaining candidates after the fifth count but was still well short of a majority. After the Liberal candidate’s preferences were distributed, the Greens candidate Adam Bandt won the seat of Melbourne with 56 percent of the final vote.

Seat of Melbourne, 2010 federal election
CandidateVotes after first countVotes after second countVotes after third countVotes after fourth countVotes after fifth countVotes after sixth count
Georgina Pearson (Family First)1,3891,4451,522 Excluded
Adam Bandt (Green)32,30832,48132,67633,37134,66450,059 Elected
Joel Murray (Australian Sex Party)1,6331,7391,9162,120 Excluded
David Collyer (Australian Democrat)602 Excluded
Penelope Green (Socialist Party of Australia)613671 Excluded
Cath Bowtell (Labour)34,02234,13434,28734,54734,98239,268
Simon Olsen (Liberal)18,76018,85719,92619,28919,681 Excluded

As the Melbourne example shows, preferential voting always produces a candidate with a majority of votes. It also shows that it may take quite a few preference distributions to achieve this result. In Melbourne, some voters may have helped to elect the candidate who was their fourth, fifth or even sixth preference. The Melbourne result in 2010 was unusual, since in most cases, the candidate with the largest first preference vote goes on to win the seat. It was particularly unusual in that minor parties almost never win lower house seats in Australian elections. The fact that a Green was elected as a result of Liberal preferences in Melbourne also shows that parties sometimes advise their voters to give preferences to candidates with whom they share little ideologically so as to inflict damage on another rival party, in this case Labor.

Preferential voting gives voters the opportunity to register support for a minor party or Independent candidate that they like, but know has no chance of winning, while using their second and later preferences to help determine who does win the electorate. For most commentators, this feature of preferential voting provides distinct advantages over first-past-the-post voting. Critics of preferential voting argue that they should not be forced to indicate preferences, even if they are low preferences, for candidates whose views they find offensive.