05 May, 2010

Why Preferential Voting Works

I’ve lost count of the number of times I’ve written this out, but if I post it here, I’ll be able to refer back to it, and with the UK election coming up tomorrow, and electoral reform on the agenda there, it’s relevant again.

Many, if not most, voting systems in countries that are universally recognised as democracies are fundamentally undemocratic.  The problem is with the simple majority, or “first past the post,” voting system.  You might think that it’s perfectly fair that whoever gets the most number of votes is duly elected.  However, that all depends on what you consider to be a majority.

Consider an election result that looks like this:

Candidate A:    40%
Candidate B:    35%
Candidate C:    25%

Under a simple majority system, Candidate A would win because he polled more votes than any other candidate.  The problem is that an overwhelming majority of 60% want someone else.   That’s just in a three-candidate election. If there were five, someone could potentially win with as little as 21% of the vote.  How is that democratic?

Simple-majority voting doesn’t elect the most wanted candidate.  It elects the least unwanted.  There’s a big difference.

Preferential voting elects the most preferred candidate.  Under a preferential system, instead of ticking a box, the voter ranks each candidate in order of preference, giving a 1 to the most preferred, a 2 to his second preference, and so on.  If no candidate has an absolute majority of 50% +1, then the candidate with the least votes is eliminated, and his second preferences distributed.  This continues until one candidate has a 50%+1 majority.

In the example above, Candidate C’s second would be counted.  Let’s say that four fifths of the people who voted for Candidate C chose Candidate B as their second preference and one fifth chose Candidate A.  That would mean that after preferences were counted, the result would be

Candidate A:    45%
Candidate B:    55%

And candidate B is duly elected as the most preferred candidate.  Although he does not have a majority of first preferences, he is clearly the most preferred candidate.

There are some places that go part way towards this system by holding run-off elections when no-one gets a clear majority.  However, these run-off elections are usually between the top two candidates.  If there are lots of candidates on the ballot, it’s possible that even the top two have less than 50% of the vote between them.  It could be that someone further down on the primary vote is actually the most preferred candidate.  Then there is the obvious expense and inconvenience of a second election.  This is why some advocates in the US refer to preferential voting as instant run-off voting.

Preferential voting also removes the problem of third-party candidates splitting a demographic, and the need to vote tactically to avoid such a split allowing less preferred candidates to sneak in.  Let’s take the example of the 1992 US presidential election:
Bill Clinton won 43.01% of the vote, George Bush won 37.45% and Ross Perot won 18.91%, which is a massive result for an independent candidate. (Source)  Perot’s vote was enough to tip the election one way or the other.  While it’s impossible to say for sure, it’s fair to suggest that Perot took more votes from Bush than from Clinton.  If two thirds of Perot voters had chosen Bush as their second preference, that would have given the election to Bush. 

I choose that example because I know a few people have me pegged as a mad, screaming leftie.  And I won’t deny that Clinton was the most preferable of the three options as far as I’m concerned.  The fact remains though, that the overwhelming majority of US voters in 1992 voted for a conservative candidate, but because there were two of them, the election went to the not-quite-so-conservative candidate.

It was, of course, a similar situation in 2000.  Ralph Nader’s 2.73% may have been paltry in comparison to Perot’s result, but that election was so close that it would still have been enough to tip Bush or Gore over 50% and the farce in Florida would be neither here nor there.  While it’s arguable as to which way Perot’s preferences might have gone, I would be gobsmacked if any Nader voters would have preferred Bush. 

With preferential voting, those who want to vote for an alternative to the major parties can do so safe in the knowledge that their preferences are recorded and their vote will not translate into a simple majority for a candidate representing the opposite party.

The movement for electoral reform in Britain seems to be advocating a system of proportional representation.  While it may be an even more representative system for electing an assembly, I have doubts about its workability.  Proportional representation makes it far easier for minor parties to be elected in numbers proportional to their support, rather than being squeezed out by the major parties on preferences.  Proportional representation almost always delivers a hung parliament.  Advocates say that hung parliaments lead to consensus government.  I can see their point.  Critics say that it allows minor parties to hold government to ransom and wield a power far greater than their numbers.  I can see that point too.  Every system has its flaws – some more than others.

In Australia, we elect the House of Representatives by preferential voting and the Senate (the states’ house and house of review) by proportional representation.  I see this as the best of both worlds.  All parochialism aside, I believe the Australian federal electoral system is the fairest there is. 


  1. Preferential voting creates the illusion of majority support, but you are still electing the least unwanted candidate. In any system where you elect only one member for a constituency, there are going to be more losers than winners.

    The Alternative Vote also stifles diversity even more than first-past-the-post.

    For everyone to be represented by someone they positively prefer, you need proportional representation.

  2. This doesn't stop people from voting against the lesser of evils or tactical voting. They just do it on a different form.

  3. I take your point that preferential voting does skew the result but I disagree that it also elects the least unwanted. I believe the important thing is that it abandons a simple notion of most wanted and instead chooses the most preferred.

    I agree that proportional representation is a fairer reflection of the electorate, but how many representatives can one constituency have? And if you widen the boundaries of electorates in order to elect multiple candidates proportionally, then what happens to local representation? You could end up with the whole of Alberta represented by a dozen people, all from Calgary.

    That's my main concern about proportional representation. There may be ways to make it work practically as a legislature, but this is why I like preferential for the lower house and proportional for the upper.

    People will always end up voting for the lesser of evils. And yes, tactical voting does occur. I should have said reduces rather than removes. One way it occurs is that people who actually want to vote for a major party (usually the incumbent) will put them second or third after some minors or independents, just to give them a scare.

  4. Preferential voting, in a two-party system, also works to eliminate the idea that people have (especially Americans) that voting for a third-party candidate is "wasting your vote".

    As you said, "With preferential voting, those who want to vote for an alternative to the major parties can do so safe in the knowledge that their preferences are recorded."

    The part of the American electoral system that leaves me the most gob-smacked is the idea that the majority winner (either democrat or republican) in a state "wins" the state, which means the electors of the winning party in that state are the only ones who vote for the presidency (and a democratic elector isn't going to vote for a republican president, and vice versa). So if a state votes 45% democrat and 55% republican, the republican electors win that state, and go on to vote for the republican candidate, which essentially means that 100% of the votes cast in that state, despite the fact that 45% of them were for the democratic candidate, went to the republican candidate.

    How on EARTH is that representative of what the people in that state want? (I hope I didn't stuff any of that up!)

    But that's a discussion for another day. :)

    By the way, have you written any posts that discuss the idea of compulsory versus voluntary voting?

  5. The original idea of the college system was to make every state count so that a candidate couldn't just focus on the major population centres and never visit the rest of the country. It was an understandable solution for making candidates spread themselves around in the 19th century but these days, we have a thing called television. The college has had its day and now it's just a scam - as is the notion that supporting minor parties is wasting your vote.

    It bewilders me that anyone is taken in by the "don't waste your vote," argument. It's not about trying to pick the winner - not in that sense. A wasted vote is voting for who you think is going to win, rather than who you want to win.

    I don't really have much to say about compulsory voting other than that I am all for it. I have no time for the nonsense about the right not to vote. This is a country that doesn't have conscription or national service. The only thing we are compelled to do is vote. Fifteen minutes of your Saturday once every three years is a small price to pay. And even then, all you really have to do is show up and have your name marked off. It's up to you what you do with your ballot paper after that - although anyone who doesn't use it correctly deserves to be mocked by small children. No matter how dull the choices are, there's always a least-worst option.

  6. OK. Just curious, because if you had written a post about it, I'd want to read it. But I suppose that paragraph is just about the same thing, really.

    I haven't read/researched enough to have made a definitive opinion on it, myself, but right now I tend to favour voluntary voting. Not because of the "right to not vote" nonsense (with you on that one), but because I don't see how compulsory voting results in an accurate representation of what a society wants.

    Those who have a solid preference will vote. Those who don't care will stay at home. The non-voters will have to make do with what they get, and if they don't like that idea, then they can go vote. People who don't give a shit will just vote for the current PM, or vote for the guy with the coolest name, or do a donkey vote. How's that accurate?

    Anyways, it's a non-issue really, because Australia is afraid of change, right? :)

  7. I understand where you're coming from, but I think there are other issues at play. Compulsory voting means you know what the turnout is going to be, so there are no "surprises" at polling booths that run out of ballot papers because they weren't expecting so many people wanting to vote.
    Another thing about the British and US systems - and many others around the world - is that they vote on a regular work day. In Britain, there have been suggestions that employers told staff that they were needed to work late that day. In fairness, those reports are unconfirmed and the constituencies where people were turned away from the polling booths were safely held seats, where the number of people who missed out would not have been enough to make a difference, but it's bound to give people ideas.

    I think compulsory voting removes that possibility of tampering and while it does lead to the donkey vote, or people voting when they don't really care, I believe that's the lesser of two evils. I don't think it's possible for compulsory voting to misrepresent the will of the people because those who vote only because they have to, are still making a choice about their vote (notwithstanding the donkey vote). I think there's far more danger of misrepresenting the view of the electorate if one group (let's say, the unions) are better at getting out the vote than another.

  8. No one is suggesting we move our voting day to a weekday if we were to introduce voluntary voting. What's wrong with leaving it on a Saturday? That removes the possibility of tampering, also.

    Running out of ballot papers isn't really a big issue. It's not like we're going to base our decision of whether to move to voluntary voting or not on that kind of thing.

    Now, if those who cared voted properly, and those that didn't care made donkey votes, then I wouldn't have a problem with compulsory voting. But that's not what happens. We have a bit of that, and a bit of: "Aw who's PM now? Howard? Yeah. He's alright. I'll just go him. Don't fix it if it ain't broke, eh love?"

    Now, of course, those people have MADE A DECISION, haven't they? But based on what? Laziness. Ignorance. That's dangerous, imo. I'd prefer if those people stayed at home and left the voting up to those of us who care about the outcome.

  9. Like I said, it's a non-issue. And considering campaigning is nothing but mud-slinging and telling the public what they want to hear (as opposed to what you're actually going to do), then really I suppose we're never going to ever have a 100% accurate result for what the people want, hm? :)

  10. Equally, voluntary voting is not going to weed out all the people who haven't thought their vote through.

    No system is perfect - it's a question of the least imperfect. Whatever the system, the country gets the government it deserves.