Wednesday, January 11, 2012

What is Preferential voting?

Preferential voting is a type of ballot structure used in several electoral systems in which voters rank candidates in order of relative preference. For example, the voter may select their first choice as '1', their second preference a '2', and so on.

The general advantage of the system is that the candidate elected reflects, or can reflect, a broader base of voters than in the one vote per voter system. So, assume one candidate is liked by 35% of the voters and hated by 65% of voters. In a race with many candidates this candidate may win if the vote is split. In a ranked vote system it is unlikely the candidate will win.

3 comments:

Anonymous said...

This is the system that elected Stephane Dion.

'nuf said.

Loraine Lamontagne said...

No, this is not the way that Dion was elected as leader of the LPC. He was chosen after many rounds of voting.

The Preferential Ballot is a one-round ballot that is used in Australia, so despised by members of my family who live there.

From wiki:

Supporters of the parties and individual candidates hand out "how to vote" cards (HTVs) at the entrance to polling stations or distributed with election material sent in the post, advising voters how to fill in their ballots to support that party or candidate. The information published on a how to vote card is a recommendation only and no voter is obliged to vote as published, but up to 80% of voters follow the recommendations of their preferred party or candidate. The proportion of voters that choose not to follow their preferred candidate's recommendations is called the "preference leakage".

Todd said...

Loraine's message seems to apply much more to the form of preferential voting used in the senate elections, when rankings after first choice often are really important and voters are asked to rank dozens of candidates.

For one-winner elections for house, your ballots stays with your first choice if your first choice gets to the final round of two -- almost always the major party candidates. So major party voter almost always have their ballot count only for their first choice of the party, so the "leakage" point makes no sense.

Preferential voting is widely used around the world. There is no chance of it being eliminated in Australia. The Canadian Wheat Board has used it for years for its elections. A recent example of it was the presidential election in Ireland.