## Sunday, 16 January 2011

### Problems with av

Ok, it's important first of all to explain that I am fully aware that very specific examples can be bandied around to 'prove' anything.

That said the mechanics involved in this example are universal.

Candidates A B C D

Fptp would say A is the winner

AV would eliminate D...

We now have
Candidate C has 4 first pref votes and 2 second pref votes.

C is eliminated. Say 1 1st pref vote goes to A. the rest goes b

And we now have our winner

B wins with seven 1st pref, three 2nd pref and two 3rd preference.
Vs
A with ten 1st pref and one 2nd pref.

Now this result sounds pretty dodgy to me as it is.

We have asked 23 people for first preferences, 6 people for a 2nd preference and 1 person for a 3rd preference.
What about the 17 people who didn't get their 2nd preference registered. Being that you only need 12 votes to win, it is very silly to ignore these 17 2nd preference votes and to go on to other people's less relevant 3rd choices.
What if all 17 had C as their second preference?
Or any other type of combination...this is still more relevant and representative than going onto 3rd preference votes.

This can mean (and will mean) that under AV, people will get elected who wouldn't under Fptp, and who wouldn't if the two most popular candidates supporters weren't ignored after their 1st preference, but were treated the same as everyone else ( or as it is known in the wider world outside the yes 2 AV club, fairly or equally).

Candidates will be voted in not on support but by the quirks of a counting system.

Under Fptp because we do not ask for preferences, we have to go with what we have.
Under AV they ask for preferences...and then ignore in most cases most of the data..so even in a four horse race someone can be elected even if they have less first, second and third preference votes than other candidates.

Notice in your example that Candidate A was nobody's second preference (except possible for some of the voters who voted for B first, but since B won, that's not important).

Out of 23 voters, 13, preferred B to A. If candidates C and D had never stood the result would be the same. If you had a deciding head to head between FPTP's winner and AV's winner, AV's winner would come out on top.

If Candidate A would win under FPTP, it would only be because of the effect of vote splitting. Candidates, B C and D all have something in common relative to candidate A. It seems that they are reaching out beyond their core voters and listening to as many people as they can. That is why B has majority support. Candidate A on the other hand is occupying a particular niche, with no rival candidates to take away any votes, but at the same time is not doing enough to attract votes from any other candidate's voters.

The fact that Candidate A gets more votes than any other individual in the first round is superficial and misleading.

If A wins, you would end up with 10 people who are happy with the result and 13 who are particularly unhappy. A minority will have got their candidate elected ahead of a majority.

One last point: It's not necessarily true that candidate A would win under FPTP. The votes described in your example are first preferences. Voters can give their first preferences without taking any risk in AV. If it were FPTP, a lot of the voters who put C and D first might have instead voted tactically for B to keep out A.

It's easy to forget that not all votes in FPTP are for the 1st preference. They could go to any preference from 1st right down to 2nd last, whichever is thought most likely to help keep out the disliked candidate.

So what you've described is not a problem with AV at all. It's how AV improves significantly on FPTP.

2. Meanwhile regarding what you say about ignoring preferences, consider which 2nd preferences aren't being counted.

It's the second preferences of the voters who put A first, and of the voters who put B first.

Those voters are getting their 1st preference counted at every stage. If someone is your first preference it means you would prefer your vote to go to them than anyone else.

If I get my first choice of anything I never feel upset that I didn't get my second or third instead. If I had wanted a different choice the most, I would have put it first.

Incidentally this is why it's also not possible to say that one person's 3rd choice is treated the same as another's 1st choice. Your 1st choice is counted from the beginning while your 3rd choice is only counted once your first two are eliminated, so your 1st choice always has more value.

Your example shows how 1st choices are always considered and have a possibility of contributing towards a winning outcome. Other preferences do not and the further down the list they are the less likely they are to be brought into play.

Supposing lots of second preferences from voters of A and B were for C. And just to satisfy your objection all the votes were transferred to 2nd preference at once and C ended up winning. The quesion would be asked "why were A and B eliminated? They had each got decent first preference votes, and more than C. Our votes should have stayed with our first choices!"

3. Meanwhile regarding what you say about ignoring preferences, consider which 2nd preferences aren't being counted.

It's the second preferences of the voters who put A first, and of the voters who put B first.

Those voters are getting their 1st preference counted at every stage. If someone is your first preference it means you would prefer your vote to go to them than anyone else.

If I get my first choice of anything I never feel upset that I didn't get my second or third instead. If I had wanted a different choice the most, I would have put it first.

Incidentally this is why it's also not possible to say that one person's 3rd choice is treated the same as another's 1st choice. Your 1st choice is counted from the beginning while your 3rd choice is only counted once your first two are eliminated, so your 1st choice always has more value.

Your example shows how 1st choices are always considered and have a possibility of contributing towards a winning outcome. Other preferences do not and the further down the list they are the less likely they are to be brought into play.

Supposing lots of second preferences from voters of A and B were for C. And just to satisfy your objection all the votes were transferred to 2nd preference at once and C ended up winning. The quesion would be asked "why were A and B eliminated? They had each got decent first preference votes, and more than C. Our votes should have stayed with our first choices!"

4. We disagree from the first paragraph, not a good start.
Everyone's full range of preferences should count.

There is no possible way to conclude that 13 people would be unhappy with A ..you haven't asked for the 2nd preference of 7 of those 13 . Unless of course people are 'unhappy' even if their second choice gets in, which means that 16 people are unhappy with B.

Tactical voting isn't included of course, and while some of this dishonest voting cancels itself out even with the estimated 9% tactical fully against A ...they'd still win.

It might not matter to B that their second preferences aren't counted, but it should matter to any no biased person wishing that the person with most support wins.

I don't think ANYONE should be eliminated. I believe everyone's full range of opinion should be counted before writing possible best options off.

5. "Everyone's full range of preferences should count. "

To an extent, yes. But don't forget it's one person one vote. You get one vote and it should go to your highest placed candidate in each round. Why would you want your vote transferred when your candidate hasn't been eliminated?

"There is no possible way to conclude that 13 people would be unhappy with A ..you haven't asked for the 2nd preference of 7 of those 13 . Unless of course people are 'unhappy' even if their second choice gets in, which means that 16 people are unhappy with B."

My mistake. I misread your post and didn't see that an extra vote was transferred to A. So it'd be 11 happy with A winning and 12 unhappy. My point is the same however.

You mention the 2nd preferences not asked for you but you're forgetting where they come from. You must always consider 1st preferences first. It's a tautology and needs no further explanation.

"Tactical voting isn't included of course, and while some of this dishonest voting cancels itself out even with the estimated 9% tactical fully against A ...they'd still win."

They'd win with a minority. Your example shows that B has a majority once voters are asked to consider just A and B, B is preferred overall.

"It might not matter to B that their second preferences aren't counted, but it should matter to any no biased person wishing that the person with most support wins."

I think your confusing 1st preferences with support. Candidate A doesn't have majority support compared to B. A beats C and D, but so does B, so it really comes down to A vs B and B wins that contest and therefore has more overall support.

There's a majority of voters who agree that they prefer B to A. The fact that some of them really prefer C or D to either of them doesn't change their preference of B over A. The problem with First Past the Post is it assumes voters don't have preferences. Voters ALWAYS have preferences, and forcing them to just choose one candidate to vote for won't magically make voters not have any other preferences.

"I don't think ANYONE should be eliminated."

I think you might want to rephrase that because you've basically just said everyone should win all the time. Not winning a seat is the same as being eliminated. Under First Past the Post all except one candidate are eliminated all at once. AV just does the elimination gradually to ensure of majority support.

"I believe everyone's full range of opinion should be counted before writing possible best options off."

Everyone's full range of opinions IS counted under AV. Your first choice gets your vote until they're eliminated. If they are eliminated then the rest of your preferences are considered. Compare that with First Past the Post which makes no attempt to recognise that voters even HAVE preferences, which brings in all the problems of tactical voting, split votes and winners without a majority.

You seem to be asking for some sort of artificial transference of votes where it's not wanted.

It's perfectly objective to say that a voter would want their vote to stay with the first preference for as long as possible. That's why it's a first preference.

6. Sorry, my mistake, I missed that one extra vote got transferred to A, so it'd be 12 vs 11 rather than 13 vs 10.

My point is the same though. B has more support than A. In a head-to-head, B would beat A. A does not have a majority.

Remember that A and B are both competing for the same votes. A has as much chance of receiving transferred votes as B. It is a fair contest.

The fact that A got more 1st preference votes than B doesn't matter when neither got a majority. Receiving a majority is absolutely crucial. Once you have a majority you can't say that all the other voters might have got together and agreed on a different candidate. Until then you just don't know whether or not you have the most support.

It's perfectly objective by the way to say it doesn't matter that 2nd preferences of voters for B and A aren't considered, because those voters are having their first preferences counted. It's a tautology to say that people are happier with their vote going to their first preference than their 2nd and should need no further explanation.

I'm not sure what you mean when you say you don't think ANYONE should be eliminated. The only way to not be eliminated under any system is to win. I doubt you're saying that everyone should always win so I'm not sure what your point is here.

Meanwhile, regarding your last point, AV does consider everyone's full range of opinion. Your vote goes to your highest placed candidate in each round. You are in fact making my case for me.

"writing possible best options off" is exactly what you'd be doing if you transferred votes away from one of the leading candidates just to include 2nd preferences of their voters for the sake of it.

7. You misunderstand what a 'preference' is - it isn't a measure of *how much* you like a candidate, only the order in which you prefer them.

One person may support their 10th preference far more than another supports their own 1st preference - neither FPTP nor AV claim to address this, just as neither claim to address 'proportionality'.

Preferences and weightings are very different thigns.

8. I think you also have a bogus statistic in there when you say:
"Being that you only need 12 votes to win, it is very silly to ignore these 17 2nd preference votes"

If you are wanting to count all preferences, then it isn't 12 votes needed to win (23/2+1) it is something like 47 (23*4/2+1) - you'd have to explain how you want them weighted though.

9. POP, disagree there. If we are talking about likelihood, if someone told you their 1st preference and someone else told you their 10th preference, what preference would you say was most likely to have a higher level or support?

Thank you in your second post for ripping AV away for me. Your right, to include extra preferences you DO need to increase the level of 'majority' but AV doesn't do that does it.