Why Stop at 50%?

I've been too negative - pointing out inaccuracies in claims made in favour of AV, when nobody really cares how the system actually works anyway; it's about the spirit of the change.

So for this post and the next, I'm going to be more positive, and suggest some alterations to the electoral system that might in some small way improve things. (And for this first one, I'm indebted to Katie Piatt for setting me along this line of thought.) Let's begin.

A supporter of First Past the Post, a supporter of AV and a third-world dictator (I won't name them) are sitting in a pub (I will name it - the Good Companions, in Brighton).

The FPTP supporter says, 'Under my system, the winning candidate has the highest number of votes.'

The AV supporter says, 'Ah! But under my system I can guarantee that the winning candidate has more than 50% of the votes.'

The dictator says, 'That's nothing. Under my system I can guarantee that the winning candidate gets 100% of the votes.'

As it turns out, both the FPTP and the AV supporter are understating their positions.

In FPTP, we can make guarantees about percentages. If there are four candidates, then it is guaranteed that the winner will get more than 25% of the votes. If there are three candidates, then it's 33%. If two, then 50% (the equivalent of the last round of AV) and if there's only one, then you can guarantee 100% support (the dictator's system).

So if we want, as AV claims, more than 50% support for the winner but still have FPTP, that's easy - we just restrict the number of candidates to two. The problem is obvious - how do we determine those two?

AV is essentially an answer to that question. It manages it all in one election, but effectively takes multiple votes across a series of elections. If there are four candidates in total then we have a vote between those four. The loser drops out and their votes are transferred to the next round of three. At this stage we can only be sure that one candidate gets at least 33%, so again we drop out the loser, transfer the votes and now have an election of two in which someone (it's mathematically guaranteed) gets more than 50% and the result is called.

But why stop there? Why halt this repeated process of dropping out the losing candidate? Now the second place candidate drops out, his votes are transferred to the only remaining candidate, and the winner can be declared as having 100% support.

But that's silly. Clearly no one believes that the winner has 100% support, in just the same way that no one believes it in a dictatorship. The winner may be the most popular candidate, but the 100% support is meaningless - it's just an inevitable consequence of the mathematics.

But in just the same way, under AV as it is proposed, the 50% is meaningless - it's just as much an inevitable consequence of the maths, a statement which though true, cannot be false. I'd like to see a winner under AV who didn't get 50% of the vote.

I say that the percentage is meaningless, but perhaps a better term is 'not interesting'. If I were to tell you that the last five presidents of France all got more than 50% of the vote in the final round, it would not be interesting. And I use the term in a slightly technical sense - by 'not interesting' I mean it provides no information that you couldn't otherwise have inferred. French presidents have to get more than 50%, just as AV candidates do - that's the system.

However, if I told you that in 2007 Sarkozy won with 53%, whereas in 2002 Chirac won with 82%, that would (might) be interesting. Clearly there was something different about Chirac's election compared with Sarkozy's. (There was - Chirac was standing against the fascist Le Pen.)

But under AV, as currently proposed, we don't get that sort of information. If I were to tell you that in one constituency the winner was Smith with 53% and in another the winner was Jones with 58% the actual percentages tell you nothing of interest. Jones my actually be less popular than Smith.

Why? Well in Jones' constituency, voting went to the final round. Jones got 58% and his opponent got 42%.

But Smith reached the 50% finishing post while there were still three candidates left. He got 53% and his opponents got 20% and 27%. If the AV process had continued to the next stage and the third place candidate had dropped out then the redistributed results might have given 63% (or more, or less) to Smith and 37% to his opponent. Now Smith's 63% can be more fairly compared with Jones' 58%.

So why is this not the way AV is proposed to work? Why do we stop counting as soon as one candidate passes 50%? Well, it could be argued (I have done) that the purpose of elections is primarily to choose an MP, not to divine other related information. But I'd also argue that getting other information is useful, if it doesn't affect the actual result, which this doesn't.

It could be argued that counting every constituency through to the final round would be expensive, but we already know that there is no additional cost to AV elections, so even if my proposal proved to be twice as expensive, twice nothing is still nothing (and that's the simplest bit of maths you're likely to see on this blog for a long time).

It could be that proponents of AV realise that if this approach were followed then in some seats (safe seats under FPTP and still safe under AV) this extra transfer of votes might mean the winner getting maybe 80% or occasionally 90%, and that's getting a bit too close to the dictator's 100% and could give away the game that all the percentages are just artefacts of the system. I doubt it, because I doubt many of AV's proponents have thought it through to that extent.

But that's my proposal. If AV succeeds at the referendum, make a slight amendment to it:

In every seat, counting should carry on to the final round of two candidates, even if a winner can be determined earlier, so that comparison of winning percentages across constituencies operates on a level playing field.

Any takers?