Public Address | Cafe | Legal Beagle: Voting in an STV election

izogi

Tue, 11 Oct 2016 09:58:29 +1300

The sad fact of the matter is, izogi, “media” workers have only ever had a very basic understanding of how STV works. That is very clear from the hopelessly incomplete and inaccurate descriptions of STV we see in our local papers, particularly around local election time.

Also, assuming it's true,…

Paul Campbell

Tue, 11 Oct 2016 09:23:24 +1300

I’m going to let you into a little secret. As you probably know, I rank-ordered 13 out of the 20 Capital and Coast DHB candidates

lucky you, the Nats took away my right to elect my local DHB this year

Paul Campbell

Tue, 11 Oct 2016 09:22:26 +1300

Given most people out there seem to compare this with FPP, claiming that FPP is more simple (and therefore better), I think it needs to be pointed out that FPP also results in votes being thrown away, except that it happens immediately for everyone whose first choice doesn’t get elected.…

izogi

Tue, 11 Oct 2016 07:00:57 +1300

unless of course all the people you choose are eliminated, then all of your vote is still in play and is thrown away ..... as I mentioned it's stupidly difficult to rank so many different people ...

Given most people out there seem to compare this with FPP, claiming that…

Steve Todd

Mon, 10 Oct 2016 18:19:02 +1300

Once again, I'm not arguing with you, Paul. In my humble, you're spot on.

"[...] why didn't I vote for all 43?" (Strictly speaking, why didn't I rank-order all 43?)

It's pretty clear to me, you didn't rank-order all 43 because you knew, deep down within, that your rankings beyond…

Paul Campbell

Mon, 10 Oct 2016 17:37:03 +1300

right but the difference is that if you had otherwise just voted for 9 your vote goes to the 10th, not the 42nd .... but, if candidates 10-41 drop out during the counting and your vote does end up residing with #42 then, well that's why you listed them in…

Steve Todd

Mon, 10 Oct 2016 14:00:04 +1300

Again, agreed. This is what Andrew Geddes suggested people might want to do, but I've heard that he actually confused people. Also, he talked about making sure you don't help the ones (plural) you don't like, whereas the "numbering all candidates" ploy only ensures you don't help elect your bottom-ranked…

Paul Campbell

Mon, 10 Oct 2016 12:50:30 +1300

unless of course all the people you choose are eliminated, then all of your vote is still in play and is thrown away ..... as I mentioned it's stupidly difficult to rank so many different people ...

However once you reach the "people I don't know enough about to vote…

Steve Todd

Mon, 10 Oct 2016 12:26:33 +1300

Rich, if you were to read the papers I linked to (at the dunedinstadium website) near the top of page 2 of this thread, particularly the first four, I doubt you would come back and say you still don't know how STV works.

For those who don't want to know…

Steve Todd

Mon, 10 Oct 2016 12:12:40 +1300

I agree with your summation, Paul, but I can't help reiterating that it was not necessary for people to rank-order all 43 candidates in order to have an effective say in the outcome. Associate-Professor Janine Hayward recommeded people just rank-order the candidates they want to see elected. I go a…

Rich of Observationz

Mon, 10 Oct 2016 10:39:03 +1300

“media” workers have only ever had a very basic understanding of how STV works

And as this thread demonstrates, people who understand STV haven't cracked being able to explain it to anyone who isn't a voting system geek.

Paul Campbell

Mon, 10 Oct 2016 08:45:51 +1300

The bulk of redistributed votes come from those left over each time a candidate reaches the threshold and has votes left over (those votes ‘left over’ are not votes of individual people, they are fractions of votes equally shared between everyone who elected the candidate which are distributed to each…

Steve Todd

Sun, 09 Oct 2016 19:52:42 +1300

I’m sure that newspaper…

izogi

Sat, 08 Oct 2016 08:51:43 +1300

The writer warned voters not to rank-order too many candidates, because “If you choose to number your preferences then your one vote can be split, supporting all of your numbered preferences depending on how the vote counting proceeds, including those that you don’t want.” (He said this had happened in…

Sacha

Sun, 02 Oct 2016 22:12:09 +1300

tempted to stop after 7

Steve Todd

Sun, 02 Oct 2016 21:49:53 +1300

Wow! Not bad. I managed 13 of 20 candidates for the C&C DHB. I didn't have sufficiently adverse opinions of the remaining seven, to "suppress" a most-disliked candidate.

I suppose you could say the moral of my story, above, was, rank-order as many or as few of the candidates as you…

Sacha

Sun, 02 Oct 2016 21:05:46 +1300

Placed my votes today for Auckland DHB (region's only STV election) and ranked all 28 candidates just to suppress the last few. Took a bit of reading in between, mind.

Steve Todd

Sun, 02 Oct 2016 19:31:25 +1300

I was casually playing around on the Internet the other day, and stumbled across the Otago University Magazine, Issue 19, February 2008, in which there was an article titled “Voting with your feet”, by Nicola Mutch. In this article, a Dr Chris Rudd (who had claimed to originally be a…

Rich of Observationz

Wed, 28 Sep 2016 10:23:48 +1300

Carpetbaggers from Porirua regularly seek office in our city – I favour building a wall.

Sacha

Wed, 28 Sep 2016 00:08:57 +1300

Ginette McDonald was the second-preference choice of 797 people

surely Tawa is north of the Southern Ward? :)

Steve Todd

Tue, 27 Sep 2016 19:35:46 +1300

Nicci—

While your understanding of how surpluses are distributed, and Graeme’s confirmation of it, are correct, your example of 2,000 votes cast and 1,334 being needed to win, could not actually happen. If two candidates are being elected, the initial quota would be 666.6666… (2000 / 3).

To give you…

Graeme Edgeler

Mon, 26 Sep 2016 22:35:50 +1300

So, 2000 votes are cast. 1334 are needed to win. One candidate gets 1500. All the second preference votes are calculated and pro-rata shared into 166 votes (ie. 1500-1334) and then that amount of votes gets allocated for the next count.

Correct.

Candidate one keeps 1334 of their votes. Which…

Nicci Coffey

Mon, 26 Sep 2016 22:08:34 +1300

You said: "For example, if the quota was calculated as being 100 votes, and on the first round, one of the candidates got 125 votes, then those excess 25 votes are distributed according to second preferences. To make it fair, the second preferences of all that candidate’s voters are used…

Rich of Observationz

Fri, 26 Aug 2016 16:23:33 +1200

But we *love* digression?

Since I don't know what your argument is for direct election of mayors (beyond 'local government is different') then I can't really come up with an alternative view. Indirectly electing council leaders does work reasonably well (for most councils in the UK) and used to work…

Steve Todd

Fri, 26 Aug 2016 15:49:19 +1200

I was waiting for this, although I assumed you would refer to Wellington, rather than Auckland.

I'll just say this: local government is different to national government. If you want to discuss governance, this is the wrong posting / thread. Besides, you're questioning me, rather than engaging in a discussion…

Rich of Observationz

Fri, 26 Aug 2016 15:39:23 +1200

Ok, so Auckland council, 1.4mln people, must have a directly elected leader.
NZ in total, 4.5mln people, must *not* have a directly elected leader.

Why?

Steve Todd

Fri, 26 Aug 2016 14:44:52 +1200

Heh, heh, it’s the garden path that’s beginning to worry me, Rich, not the rabbit hole.

First, I’ll say that, in our Westminster system, the office of prime minister should never be directly-elected. The experience of Israel turns me right off that notion (not that I ever had it).

If…

Rich of Observationz

Fri, 26 Aug 2016 13:47:05 +1200

Without going down the rabbit hole, do you believe that we should then adopt the American/French system where the head of government (an even more important post) is also elected directly by the 'people'.

Steve Todd

Fri, 26 Aug 2016 13:21:23 +1200

Okay, that didn't work.

Try this: http://publicaddress.net/system/cafe/hard-news-ge2015-proper-mad/?p=340160#post340160 .

Steve Todd

Fri, 26 Aug 2016 13:19:42 +1200

(I’d note that an indirect election would be fairer here in a couple of ways:- a council would be elected with members split maybe 39/34/27 R/VPP/D

Etc.

Yes, what you say here could work in theory, but, unfortunately, at the time, the 14-seat Burlington City Council was elected by single-seat…

Steve Todd

Fri, 26 Aug 2016 12:06:49 +1200

Your summation is pretty much spot-on. The only correction I would make being that the Republicans could have achieved a *better* outcome for themselves if 750 of them had given their first round support to the Progressive candidate, not to the Democrat. That way, the Republican candidate would have been…

Rich of Observationz

Thu, 25 Aug 2016 19:39:02 +1200

Incidentally, it would be interesting how NZ would elect an executive president (or directly elected PM, put another way) using STV.

In current conditions, I'd think that NZ First would be the first major party eliminated. Should National lack an overall majority (with ACT and Dunne preferences, and assuming all…

Rich of Observationz

Thu, 25 Aug 2016 19:33:19 +1200

So, avoiding technicalities:
– Burlington has a substantial natural majority for the liberal-left.
– there was a right-wing candidate and two left wing candidates.
– because of this, the Republican candidate led the first round. The Democrat was eliminated.
– Both the Republican and the Progressive’s second preferences were of…

Steve Todd

Wed, 24 Aug 2016 18:17:52 +1200

Again, this (the 2009 Burlington mayoral election) is a so-called monotonicity violation, detected after the fact. The first-preference votes given for the three main candidates were: Wright (Republican) 2,951; Kiss (Vermont Progressive Party) 2,585; and Montroll (Democratic) 2,063.

According to Donald Marron, here: https://dmarron.com/2010/09/19/the-feud-over-the-2009-burlington-mayoral-election/ if about 750 of Wright’s supporters…

Tim McKenzie

Tue, 23 Aug 2016 18:12:44 +1200

For the rest of us, can you produce a real life instance where an STV election in NZ has produced an outcome you regard as unfair because of the counting system?
In New Zealand? Probably not. As izogi pointed out, the vote data just isn't available. A little effort was…

Michael Homer

Fri, 19 Aug 2016 17:52:07 +1200

I note your comment [...] that it would be "fairly inefficient at run time with a large number of candidates."I was mostly talking about my own implementation there – I built it directly off the definitions, rather than efficiently. For a proper implementation computation cost wouldn't be an issue other…

Steve Todd

Fri, 19 Aug 2016 10:48:18 +1200

I've read the Wikipedia article again, this time more carefully, and I see that the Schulze method does indeed provide for equality of preference. (My apologies, Tim.)

I note your comment about it being less intuitive, and that it would be "fairly inefficient at run time with a large number…

Michael Homer

Thu, 18 Aug 2016 21:42:37 +1200

I'm not planning to use it for anything, no, it just seemed interesting to write. It's not complicated and there are better implementations around.

If the ballot records were available I might've given it a go, but they're not.

izogi

Thu, 18 Aug 2016 18:00:42 +1200

It'd probably have to be tested on data taken from somewhere other than a real local election in New Zealand. Section 89 of the Local Electoral Act appears to say that all voting documents must be destroyed after 21 days of secure storage, or as long as it takes for…

Brent Jackson

Thu, 18 Aug 2016 14:24:05 +1200

You planning to use your program for anything ?

If you have access to any old STV election data, it'd be interesting to pump it through your program, and compare the results to see if they ever differ. I'm guessing that it is unlikely to ever make a difference in…

Steve Todd

Wed, 17 Aug 2016 16:38:13 +1200

Wow! Thanks Michael. That is actually great news. (Also, it confirms how much I know about computer programming, which is nothing.)

My problem with Tim is that, Graeme puts up these posts as a public service, but Tim just wants to argue the system he’s talking about is not nearly…

Michael Homer

Wed, 17 Aug 2016 15:45:25 +1200

In contrast, it is also very clear to me that Schulze STV must indeed be extremely tedious to programIt's not. I just did it; it took maybe half an hour, directly off the "Computation" section of the Wikipedia article you linked.

To produce a program that also allows for EQP…

Steve Todd

Wed, 17 Aug 2016 11:42:47 +1200

That must be directed at Tim.

I certainly can't. Besides, I'm very happy with our vote-counting system.

Steve Todd

Wed, 17 Aug 2016 11:37:29 +1200

But your highest-ranked candidates might also do worse if you refrain from listing remaining candidates. So in practice, why would a well-informed voter want to refrain from listing their remaining candidates?

Because they don’t know them, have (little or) no knowledge of them, and no interest in them.

As I…

Rich of Observationz

Wed, 17 Aug 2016 11:29:46 +1200

I do maths and stats as part of my job, but I really can't dedicate any time to getting into Condorcet winners and the like. Life is too short.

For the rest of us, can you produce a real life instance where an STV election in NZ has produced an…

Steve Todd

Wed, 17 Aug 2016 11:28:18 +1200

But given the choice, would “ordinary people” prefer that votes belong to candidates, or that votes belong to voters?

I’ve no idea what other people think, but, in my view, votes belong to the voters, which they give *for* candidates, not *to* candidates.

In that case, your claim that “There…

Steve Todd

Wed, 17 Aug 2016 11:20:58 +1200

I have now had a chance to read through the posts you put up on Friday afternoon. I think it’s fairly clear that our toing and froing is turning people off, and that we are starting to repeat ourselves. Nevertheless, you have made some comments that I must respond to.…

Steve Todd

Wed, 17 Aug 2016 00:16:44 +1200

Yeah, I reckon I helped elect folks I didn’t want elected :-).

But by doing that, you made sure you didn't help elect those you *really* didn't want. So don't worry, you did good.

However any of us vote, it's all in the 'spirit' of STV. We can rank-order just…

Katharine Moody

Tue, 16 Aug 2016 23:56:11 +1200

Yeah, I reckon I helped elect folks I didn't want elected :-). I've lived both in Kapiti and Palmy since STV came in. And yes, this time we'll just ignore the rest.

I'm not sure that's in the 'spirit' of STV, but I tried :-).

Steve Todd

Tue, 16 Aug 2016 23:31:08 +1200

Hence, I don’t like STV.

But, Katharine, it's just the same under multiple-FPP (whether or not in wards).

It's really hard for one person "to influence an STV vote [election]", especially if no-one else, or very few other people, vote the same way as you.

Being in Palmy (15 elected…

Katharine Moody

Tue, 16 Aug 2016 22:53:02 +1200

Are there any ordinary people who’ve made it this far through the discussion, and want to comment?

Yep, I’m an ordinary voter who read the entire thread. Why did I read it in its entirety?

I’ve never been convinced about the later-no-harm claim of STV but (for some reason) because…

Steve Todd

Sat, 13 Aug 2016 09:34:24 +1200

Ha!! If that had happened, Bowtell would have been eliminated (instead of the Liberal candidate) and the Greens would still have taken the seat (which they still hold, two elections later).

Okay, that's a mistake. Bowtell would simply have dropped down to second place; the Liberal candidate would still have…

linger

Fri, 12 Aug 2016 22:58:38 +1200

it would be absurd not to elect ABCD in the example I gave.
Again, this depends on the system’s starting assumptions. I am not convinced that it is automatically absurd not to exclude E; candidate E has by far the widest support among the voter population, even though this is…

Steve Todd

Fri, 12 Aug 2016 21:00:04 +1200

You invite me to do a lot of work, and get back to you with the result of my endeavours. I don’t need to do that, Tim; I’ve got what I want (well, I wish all councils would take up the STV option). You’re the one who has some really…

Steve Todd

Fri, 12 Aug 2016 20:44:43 +1200

Wikipedia’s article on the monotonicity criterion has a section on real-life monotonicity violations that mentions two elections in Australia: one in which it was shown after the election that monotonicity was violated (in that if somewhere between 31 and 321 Liberal supporters had switched their votes to Labor, then the…

Steve Todd

Fri, 12 Aug 2016 20:39:36 +1200

Despite saying I’d “leave it that”, I have given further thought to your responses on Wednesday 10 August, particularly regarding nonmonotonicity. This is the first of three posts.

(I have seen your latest postings – at 7.30 on Friday night). I’ve had a quick look, but, I’m sorry, I’m on…

Tim McKenzie

Fri, 12 Aug 2016 16:49:08 +1200

the Aussies have completely ruined STV ... The parties also hand out how-to-vote cards which, I understand, most people follow. So, it would not have been too difficult for polling to reveal that a monotonicity violation was in the offing. Such violation could not be revealed in respect of, say,…

Tim McKenzie

Fri, 12 Aug 2016 16:43:31 +1200

I emphasise that I prefer later-no-harm because it gives ordinary voters the confidence to rank the candidates in their true order of preference.
No matter how many times you say this, it still won't be true — unless, perhaps, by "ordinary voters" you mean people who have heard and believed…

Tim McKenzie

Fri, 12 Aug 2016 16:37:34 +1200

I think you want STV with equality of preference. It can be done. David Hill’s STV program provides for it, but he only allows a maximum of 10 candidates having the same EQP. If you provide for much more than that, certainly 35 or more candidates able to have the…

Steve Todd

Wed, 10 Aug 2016 18:20:37 +1200

Thanks, Brent.

Again (groan), I forgot to separate out (from the 'M') the full-stop.

Steve Todd

Wed, 10 Aug 2016 18:14:04 +1200

Please correct me if I’m wrong, but I think you’re thinking of a “vote” as something that a voter gives to a particular candidate, as in FPP.

Thank you, Tim, for spending so much time responding to my (I suppose) criticisms. I am about done now, having spent the last…

Brent Jackson

Wed, 10 Aug 2016 16:40:08 +1200

Thanks for that Steve. The correct link is this.

linger

Wed, 10 Aug 2016 15:59:05 +1200

“Correct winner” is a circular term here; it’s “whoever wins under the stipulated rules of vote-counting”, those rules being the present subject of discussion.

One could imagine an alternative vote-counting system that considered all rankings simultaneously as weighted votes – e.g. as a first approximation, with a weighting of 1/(2^rank),…

Steve Todd

Wed, 10 Aug 2016 15:46:41 +1200

Have a look at this paper, Brent: http://www.votingmatters.org.uk/ISSUE13/P4.HTM.

I think you want STV with equality of preference. It can be done. David Hill's STV program provides for it, but he only allows a maximum of 10 candidates having the same EQP. If you provide for much more than that, certainly…

Tim McKenzie

Wed, 10 Aug 2016 15:18:09 +1200

how about at least explaining to us why you are “still not persuaded that later-no-harm is more important than having majority support for the winner, wherever possible.” Explain to us why it is worthwhile to give up later-no-harm so that the majority winner – let’s call it the Condorcet winner…

Tim McKenzie

Wed, 10 Aug 2016 15:13:17 +1200

I think I'm starting to understand at least part of the reason for our difference of opinion. Please correct me if I'm wrong, but I think you're thinking of a "vote" as something that a voter gives to a particular candidate, as in FPP. But unlike FPP, you're allowing the…

Tim McKenzie

Wed, 10 Aug 2016 15:06:30 +1200

Later-no-harm insists that a particular kind of tactical voting is unnecessary and impossible.

Does it. Why not explain how?
I worded that badly. It would have been better for me to say "Later-no-harm insists that a particular kind of tactical voting should be unnecessary and impossible". The kind of tactical…

Brent Jackson

Wed, 10 Aug 2016 15:02:41 +1200

In fact, I consider NZ STV is about as far as we can go in the refinement-manageability-public understanding trade-off in the single transferable vote

The one change I would like to see is a mechanism to reduce invalid ballots, which would also allow a person to rank the candidates they…

izogi

Wed, 10 Aug 2016 13:50:00 +1200

Consequently from (C) and at least when compared with something like FPP, I'd add (D): There is a much lessened incentive for potential candidates (and their parties) to conspire to reduce voters' choice by withdrawing candidacy for fear of splitting the vote against a mutually disliked opponent.

Steve Todd

Wed, 10 Aug 2016 12:09:03 +1200

I’m absolutely fine with STV, and what anomalies remain don’t really concern me either.

Graeme, rest assured, I have never doubted that you are, at the very least, very kindly disposed towards STV. You wouldn’t do what you do here, and make the supportive comments about STV here and elsewhere,…

Graeme Edgeler

Tue, 09 Aug 2016 22:17:45 +1200

STV’s so-called defects are not properties, if that’s the right word, that ordinary voters in large public elections can in any way take advantage of.

I’m absolutely fine with STV, and what anomalies remain don't really concern me either.

Steve Todd

Tue, 09 Aug 2016 21:52:58 +1200

But, like nonmonotonicity, the no-show paradox, etc., G-S can only be demonstrated with artificial examples. STV's so-called defects are not properties, if that's the right word, that ordinary voters in large public elections can in any way take advantage of.

I'm obviously biased, but, although they're all very interesting, they're…

Graeme Edgeler

Tue, 09 Aug 2016 21:12:23 +1200

What proof do have that STV “certainly doesn’t have that property?”

The Gibbard–Satterthwaite theorem?

Steve Todd

Tue, 09 Aug 2016 20:51:15 +1200

Do you really want to insist that this would be the correct result, even though more than three quarters of all the voters would have preferred E to win?

Yes, I do want to insist that. If more than three-quarters of voters preferred E to win, then why didn’t they…

Steve Todd

Tue, 09 Aug 2016 20:42:39 +1200

Later-no-harm insists that a particular kind of tactical voting is unnecessary and impossible.

Does it. Why not explain how?

But why is it more important to rule out that kind of tactical voting, while ignoring all the other possible kinds?

As previously stated, it gives voters the confidence to rank-order…

Steve Todd

Tue, 09 Aug 2016 19:21:45 +1200

Here I have to disagree – your second and subsequent preferences are more than contingency choices … for example if you and your neighbours give candidate A twice as many votes as they need to be elected then a full 1/2 of your vote is still live and will pass…

Tim McKenzie

Tue, 09 Aug 2016 12:52:05 +1200

Tactical voting is possible in all fair electoral systems with more than two candidates.
This is true, but it only makes the later-no-harm criterion seem even more peculiar. Later-no-harm insists that a particular kind of tactical voting is unnecessary and impossible. But why is it more important to rule out…

Craig Young

Tue, 09 Aug 2016 09:07:10 +1200

It's interesting that STV is still used in so few local body elections, and only where strong centres of MMP electoral reform acivism were before 1993. As others have noted, one drawback is the perceived logistical challenge of calculating the flow of preferences and the end result. Is another the…

Paul Campbell

Mon, 08 Aug 2016 22:39:08 +1200

Second and subsequent preferences are contingency choices only, whereby the voter is saying (to the electoral officer / STV calculator), if my first preference candidate does not need all of my vote, or is excluded from the count, I want my vote to be transferred, in whole or in part,…

Steve Todd

Mon, 08 Aug 2016 21:43:03 +1200

And it appears to limit the ability to change the alignment of councils – if there's a Green, Labour and National candidate with name recognition and good campaigns, they'll all get elected even though the Green might be on 40% and the Nat on 25%.

Rich--

Have a look at…

Steve Todd

Mon, 08 Aug 2016 20:21:07 +1200

I think it’s really smaller than that as it only requires half that many mistakes to turn it around.

No, by the end of the count, those 43 votes (approx.) will be the difference between the 2,535.817272399 votes (across several thousand voting documents) for Colin Weatherall, and the 2,492.840680897 votes…

Steve Todd

Mon, 08 Aug 2016 19:35:51 +1200

Tim, a voter may well want both A and B to win, but that is not the point. Under STV, every voter has one vote, which they express by giving their first preference to the candidate *for whom they vote*.

Second and subsequent preferences are contingency choices only, whereby the…

Paul Campbell

Mon, 08 Aug 2016 19:21:48 +1200

Both Bev Butler and yourself have nothing to worry about. Very briefly, a 43-vote difference between candidates, in an NZ STV (Meek’s method) election, where 32,820 votes were cast, is huge. That is not in any way close, as it might be in an FPP election.

I think it's really…

Steve Todd

Mon, 08 Aug 2016 18:54:10 +1200

But it’s a judgment call as to what particular criteria you want a voting system to meet. It cannot meet them all.

Agreed, but it's hard to imagine an informed electorate giving up later-no-harm in preference to guaranteeing the election of the Condorcet candidate 100% of the time instead of…

Steve Todd

Mon, 08 Aug 2016 17:55:51 +1200

Paul, I'm responding to your post where you say you're an STV fan.

See my four responses here: https://dunedinstadium.wordpress.com/2010/10/09/local-govt-online-for-results/#comments starting with the one at 10.37 a.m. on October 21 [2010].

Both Bev Butler and yourself have nothing to worry about. Very briefly, a 43-vote difference between candidates, in an NZ…

Steve Todd

Mon, 08 Aug 2016 17:35:10 +1200

My understanding is that with single-member electorates it is not proportional at all, and with multi-member it is somewhat locally proportional.

Moz, we call all STV elections in NZ, whether single- or multi-seat, Single Transferable Voting, rather than M-PV and STV, respectively. That is because, back in 2000, DIA officials…

Steve Todd

Mon, 08 Aug 2016 17:26:19 +1200

Tim—

We don’t want single-seat STV (M-PV; AV; IRV; etc.) to satisfy the Condorcet criterion, because, “The Condorcet criterion is … incompatible with the later-no-harm criterion”. (I've just noticed you've seen that (on page 2), but here goes, anyway.)

The feature of STV, that later preferences cannot harm earlier preferences,…

Steve Todd

Mon, 08 Aug 2016 17:23:53 +1200

Some more reading material here: https://dunedinstadium.wordpress.com/2010/08/26/in-defence-of-stv-2/ just after the post, and before the 34 responses.

Graeme Edgeler

Mon, 08 Aug 2016 16:46:14 +1200

And in multiple-winner STV elections, later-no-harm seems likely to harm voters’ preferences over the sets of possible winners.

Tactical voting is possible in all fair electoral systems with more than two candidates.

Tim McKenzie

Mon, 08 Aug 2016 16:08:10 +1200

Slightly too late to edit my post:

I've just noticed that, according to Wikipedia, The Condorcet criterion is incompatible with later-no-harm. If that's right, then I guess we can't both be satisfied, but I'm still not persuaded that later-no-harm is more important than having majority support for the winner, wherever…

Tim McKenzie

Mon, 08 Aug 2016 15:50:06 +1200

I quite like STV because it meets the later no harm criterion (where you cannot harm the election prospects of a candidate by ranking additional candidates lower than them).
As opposed to ranking additional candidates above them? I'm being a bit cheeky there; I assume that what you meant is…

Graeme Edgeler

Mon, 08 Aug 2016 14:00:04 +1200

I haven’t yet thought this through to the point of my brain sizzling, but wouldn’t there be theoretical scenarios where there simply wouldn’t be a candidate who could beat every other candidate in a two way race?

Yes. It's possible to have a race with no condorcet winner. The complaint…

Graeme Edgeler

Mon, 08 Aug 2016 13:45:51 +1200

Hold on. I live in Lower Hutt, and get to vote for members of the Greater Wellington Regional Council, but the Hutt City Council elections won't be STV, will they?

You're right. That was misleading. I listed all the councils that will use STV and Hutt City Council elections won't…

Moz

Mon, 08 Aug 2016 13:21:50 +1200

Yes, but that's not the question being asked. "A candidate who would beat each alternative in a 2-way match" by definition isn't your scenario. Your scenario can, and possibly does, occur, but the condorcet systems are designed to hide that possibility.

STV is designed to make is possible for a…

izogi

Mon, 08 Aug 2016 13:14:50 +1200

that is, it can fail to elect someone who would beat every other candidate in a two-way race. There are systems that do satisfy the Condorcet criterion.

I haven't yet thought this through to the point of my brain sizzling, but wouldn't there be theoretical scenarios where there simply wouldn't…

Tim McKenzie

Mon, 08 Aug 2016 13:02:47 +1200

I understand STV as the best method when (unfortunately) electing a single candidate to a position.
That's dubious. STV doesn't satisfy the Condorcet criterion; that is, it can fail to elect someone who would beat every other candidate in a two-way race. There are systems that do satisfy the Condorcet…

izogi

Mon, 08 Aug 2016 13:02:40 +1200

'counting' (typing it in to the computer)

Is this done manually? Somehow I'd assumed there was a scanning process to read voting papers, maybe with real people looking more closely at the rejects.

Rich of Observationz

Mon, 08 Aug 2016 13:02:00 +1200

*All* methods of directly electing a single candidate to an office such as mayor / president are disproportionate and undesirable -> a candidate can be elected on 51% of the votes and the 49% that didn't elect them will have no say.

(and in the case of a council, the…

Paul Campbell

Mon, 08 Aug 2016 13:01:29 +1200

What I don’t understand are the ramifications of multi-member STV contests. In Wellington, we have two or three seats in each ward, and (some) parties choose to endorse candidates – but they only ever endorse one candidate in any ward.

I think it's more an issue of branding ....

Is…

Moz

Mon, 08 Aug 2016 12:58:47 +1200

Is that because putting up more candidates would reduce the chances of any one of them winning?

In general, yes. Australia has settled on "how to vote cards" given to voters as they enter the polling booth, and widespread publishing of party lists (including on the ballot paper). New Zealand…

Tim McKenzie

Mon, 08 Aug 2016 12:52:51 +1200

If you live in the Greater Wellington Area all of your elections will be STV
Hold on. I live in Lower Hutt, and get to vote for members of the Greater Wellington Regional Council, but the Hutt City Council elections won't be STV, will they?

Rich of Observationz

Mon, 08 Aug 2016 12:52:22 +1200

I understand STV as the best method when (unfortunately) electing a single candidate to a position.

What I don't understand are the ramifications of multi-member STV contests. In Wellington, we have two or three seats in each ward, and (some) parties choose to endorse candidates – but they only ever…

Moz

Mon, 08 Aug 2016 12:50:32 +1200

STV ... It is generally considered a proportional voting system.

My understanding is that with single-member electorates it is not proportional at all, and with multi-member it is somewhat locally proportional.

In other words, if across the country each electorate has one winning candidate, a party with a solid 55%…

Paul Campbell

Mon, 08 Aug 2016 12:40:03 +1200

BTW I'm an STV fan, but I should point out a couple of down sides:

– scrutineers are practically impossible, at least here in Dunedin, 'counting' (typing it in to the computer) is done 300km (in Chch) away over a period of 3 weeks – a scrutineer would have to…

Paul Campbell

Mon, 08 Aug 2016 12:33:42 +1200

the quota is still calculated using number of seats + 1, even after the first person is elected.

oops you're right – however my main point is that the number of effective votes still in play decreases as people who haven't ranked all 40 (and who can reasonably do that?)…

Graeme Edgeler

Mon, 08 Aug 2016 12:20:07 +1200

I’d thought giving no ranking would hurt a candidate more than a low ranking.

Lots of people do. That's why I post this every time we have an ranked vote election :-)

What happens if you don’t number all candidates sequentially? E.g.

Candidate A: rank 1
Candidate B: no ranking…

James Littlewood*

Mon, 08 Aug 2016 12:15:18 +1200

Interesting. I'd thought giving no ranking would hurt a candidate more than a low ranking.

What happens if you don't number all candidates sequentially? E.g.

Candidate A: rank 1
Candidate B: no ranking
Candidate C: rank 3

Invalid?

Graeme Edgeler

Mon, 08 Aug 2016 12:03:43 +1200

(still in minor nit territory) true for the last seat, but it’s really “if anyone has NUMBER-OF-OUTSTANDING-VOTES/(NUMBER_OF_OUTSTANDING SEATS+1) votes then they’re elected”

That was because I was using an example where you needed two candidates. Also, it's not number of outstanding seats + 1, the quota is still calculated using…

Paul Campbell

Mon, 08 Aug 2016 11:56:45 +1200

If anyone now has a majority of the remaining votes, they’re elected.

(still in minor nit territory) true for the last seat, but it's really "if anyone has NUMBER-OF-OUTSTANDING-VOTES/(NUMBER_OF_OUTSTANDING SEATS+1) votes then they're elected" otherwise you discard the lowest polling candidate and redistributing their votes, if they were the last…

Graeme Edgeler

Mon, 08 Aug 2016 11:45:05 +1200

Hospital Board voting is only silly if the government hasn’t taken away your right to vote for your local hospital board

My view is that we should elect people into positions where they make decisions (especially decisions around funding levels), and not elect people into positions where they are administering…

Graeme Edgeler

Mon, 08 Aug 2016 11:40:53 +1200

Minor nit: the quota changes downwards during the voting, largely because people don't rank all 40 odd (in Dunedin's case) candidates

I did include an acknowledgement of that in an earlier question, but I accept if you were only reading that, then it could be a bit misleading:

If anyone…

Paul Campbell

Mon, 08 Aug 2016 10:53:30 +1200

Minor nit: the quota changes downwards during the voting, largely because people don't rank all 40 odd (in Dunedin's case) candidates, the quota is calculated from the number of votes still in play (including fractional bits) and the number of unelected seats still in play.

Of course Hospital Board voting…

Graeme Edgeler

Mon, 08 Aug 2016 10:32:58 +1200

Graeme, does the supercity enabling legislation still block Auckland from adopting an STV electoral system if it so desired?

Not as far as I can see. That was only for the 2010 election.

Craig Young

Mon, 08 Aug 2016 09:45:18 +1200

Graeme, does the supercity enabling legislation still block Auckland from adopting an STV electoral system if it so desired?

Graeme Edgeler

Mon, 08 Aug 2016 09:17:49 +1200

PS I am happy for people to swipe this and post it elsewhere. If you'd like a shorter or edited version, please get in contact. I'm happy to proofread something like this for anyone (even professional publications) without charge.

Public Address

Mon, 08 Aug 2016 09:17:49 +1200

Discussion from blog post.