[EM] eliminate the plurality loser until there is a Condorcet winner

[fsimmons at pcc.edu]

robert bristow-johnson wrote ...

> i *know* i loosened a few IRV supporters here in Burlington. 
> but, 
> unfortunately, the "Keep Voting Simple" side that brought us 
> back to 
> Plurality and Delayed Runoff believe that God herself has 
> ordained the 
> vote-for-only-one ballot. we won't be revisiting anything with 
> a 
> ranked ballot again in my lifetime. 

If they are dead set against anything except "vote-for-only-one" ballots, then the best they can do is Asset 
Voting.

Kristofer Munsterhjelm wrote ...

> Whether or not they're pursuing IRV for its own sake (and think 
> it's a
> good singlewinner method) or they're doing it to have IRV be a 
> steppingstone to STV, I don't know.

Asset Voting is just as simple in its single and multi- winner forms, so IRV has no advantage here over 
Asset Voting.  

----- Original Message -----
From: election-methods-request at lists.electorama.com
Date: Thursday, May 12, 2011 12:01 pm
Subject: Election-Methods Digest, Vol 83, Issue 14
To: election-methods at lists.electorama.com

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> Today's Topics:
> 
> 1. Re: eliminate the plurality loser until there is a Condorcet
> winner (fsimmons at pcc.edu)
> 2. Re: electing a variable number of seats (fsimmons at pcc.edu)
> 3. Re: eliminate the plurality loser until there is a Condorcet
> winner (robert bristow-johnson)
> 4. Re: eliminate the plurality loser until there is a Condorcet
> winner (Kristofer Munsterhjelm)
> 
> 
> -----------------------------------------------------------------
> -----
> 
> Message: 1
> Date: Wed, 11 May 2011 19:51:24 +0000 (GMT)
> From: fsimmons at pcc.edu
> To: election-methods at lists.electorama.com
> Subject: Re: [EM] eliminate the plurality loser until there is a
> Condorcet winner
> Message-ID: 
> Content-Type: text/plain; charset=us-ascii
> 
> 
> James Green-Armytage asked
> 
> Quick question for everyone: Do you happen to know when the 
> method 
> described in the subject line (eliminate the plurality loser 
> until 
> there is a Condorcet winner) was first proposed?
> 
> Forest's attempt at an answer:
> 
> I don't know about "first proposed," but I know that we 
> considered it in passing
> when we came up with the DMC proposal, one of whose many 
> formulations is to
> eliminate the approval loser (or candidate ranked on the fewest 
> number of
> ballots) until there is a Condorcet Winner.
> 
> We settled on Approval instead of Plurality as the basis for 
> elimination because
> it seemed a lot better at the time. It turns out that DMC is 
> monotonic, for
> example, while the Plurality based method is not.
> 
> Long before that (about ten years ago) I suggested a lot of 
> different tweaks on
> IRV that would make it Condorcet compliant in an attempt to show 
> IRV supporters
> how easy it would be to keep IRV from discarding the "true 
> majority winner." 
> Mike Ossipoff advised me to forget it, because (having been 
> rebuffed himself
> after proposing all of these ideas and more) he had found out by 
> sad experience
> that the hard core IRV supporters were too closed minded to even 
> consideranything other than pure Hare/STV/AV/IRV. Since that 
> time I have found a few
> staunch IRV supporters that are willing to think about other 
> possibilities, but
> on the whole Mike seems to have been right.
> 
> 
> ------------------------------
> 
> Message: 2
> Date: Thu, 12 May 2011 00:35:07 +0000 (GMT)
> From: fsimmons at pcc.edu
> To: election-methods at lists.electorama.com
> Subject: Re: [EM] electing a variable number of seats
> Message-ID: 
> Content-Type: text/plain; charset=us-ascii
> 
> 
> Raph Frank wrote ...
> ________________________________________
> On Fri, Feb 18, 2011 at 7:54 AM, Juho Laatu > yahoo.co.uk> wrote:
> > If you want to keep this property, the approach proposed by 
> Michael Rouse could determine
> > the number of board members. If most votes go to few 
> candidates, then there would be 5 members
> > (with different weight). If the votes are more distributed, 
> then all candidates (up to 9 candidates)
> > that get support over some agreed limit would be elected. 
> Alternatively one could use the number
> > of unrepresented votes as the criterion on how many members to 
> elect. This approach would
> > improve proportionality and keep the size of the board small 
> at the same time.
> 
> You could still use PR-STV to give a proportional result.
> 
> There is a formula which defines the "effective number of parties".
> It is also used in economics to define how many firms there are 
> in a
> market.
> 
> The formula is
> 
> 1/sum((vote share squared))
> 
> So, if the first choice totals were
> 
> A: 20%
> B: 30%
> C: 15%
> D: 12%
> E: 18%
> F: 5%
> 
> The result gives:
> 
> 1/(0.2*0.2 + 0.3*0.3 + 0.15*0.15 + 0.12*0.12 + 0.18*0.18 + 
> 0.05*0.05) = 4.96
> 
> This says that there are around 5 groups in the vote, which is 
> about right.
> 
> If the voters were less concentrated, you get a larger number
> 
> A: 8%
> B: 12%
> C: 7%
> D: 14%
> E: 6%
> F: 10%
> G: 9%
> H: 11%
> I: 4%
> K: 19%
> 
> would give 8.56
> 
> The rule could be that you use that formula using the first choice
> votes and round to the nearest whole number between 5 and 9.
> 
> Also, a property of the formula is that if the votes are exactly
> evenly distributed, then the number will be equal to the number of
> candidates. For example, if there were 8 candidates and each got
> exactly 1/8 of the vote, then the number of seats would be equal 
> to 8.
> 
> You can then use standard PR-STV with that number as the seats target.
> 
> Forest replies:
> 
> Or, once you have decided on the number n of seats. you could 
> complete the election with Asset 
> Voting: the candidates get together and negotiate the 
> redistribution of votes until n candidates have the 
> quota of 100%/(n+1) or more of the votes. If (n+1) candidates 
> tie with exactly this quota, then elect all of 
> the tied candidates.
> 
> This way you wouldn't have to have each voter rank the candidates.
> 
> 
> 
> ------------------------------
> 
> Message: 3
> Date: Wed, 11 May 2011 21:35:16 -0400
> From: robert bristow-johnson 
> To: fsimmons at pcc.edu
> Cc: election-methods at lists.electorama.com
> Subject: Re: [EM] eliminate the plurality loser until there is a
> Condorcet winner
> Message-ID:
> <01A95879-44B7-438F-9299-4A54B14C10FA at audioimagination.com>
> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
> 
> 
> On May 11, 2011, at 3:51 PM, fsimmons at pcc.edu wrote:
> 
> >
> > James Green-Armytage asked
> >
> > Quick question for everyone: Do you happen to know when the method
> > described in the subject line (eliminate the plurality loser until
> > there is a Condorcet winner) was first proposed?
> 
> by Plurality Loser, do you mean the candidate who was ranked 1st 
> the 
> fewest times or the candidate ranked last the most times (all 
> who are 
> unranked are tied for last place)?
> 
> i made mention of either in a paper i wrote in 2009 ("The 
> Failure of 
> Instant Runoff Voting to accomplish the very purposes for which 
> it was 
> adopted: An object lesson in Burlington Vermont") right after i 
> figgered out that the Condorcet winner was not the same as the 
> IRV 
> winner (and happened to be the candidate i supported).
> 
> i would think that this would have preceded by anyone thinking 
> about 
> Condorcet cycle for a minute.
> 
> > Forest's attempt at an answer:
> >
> > I don't know about "first proposed," but I know that we 
> considered 
> > it in passing
> > when we came up with the DMC proposal, one of whose many 
> > formulations is to
> > eliminate the approval loser (or candidate ranked on the 
> fewest 
> > number of
> > ballots) until there is a Condorcet Winner.
> >
> > We settled on Approval instead of Plurality as the basis for 
> > elimination because
> > it seemed a lot better at the time. It turns out that DMC is 
> > monotonic, for
> > example, while the Plurality based method is not.
> >
> > Long before that (about ten years ago) I suggested a lot of 
> > different tweaks on
> > IRV that would make it Condorcet compliant in an attempt to 
> show IRV 
> > supporters
> > how easy it would be to keep IRV from discarding the "true 
> majority 
> > winner."
> 
> i was impressed with the bottom-two runoff (BTR) in that it's 
> such a 
> small change to the existing IRV method used in a few places 
> (and used 
> to be in my place).
> 
> but i've been thinking that, while BTR or some other Condorcet 
> compliant IRV is better than a Condorcet non-compliant IRV, it's 
> still 
> IRV and the actual method of tabulation does not allow for 
> precinct 
> summability. if you demand precinct summability (for reasons of 
> 
> transparency in elections), then it really has to be a simple 
> Condorcet method where you count pairwise tallies locally, post 
> publicly and transmit upward the pairwise subtotals. the 
> election 
> should be decided solely by the totals from the pairwise 
> subtotals. 
> if Ranked Pairs or Schulze is used, the difference between 
> totals of a 
> pair of candidates, the "defeat strength", is part of the 
> decision, 
> but it is a derived value from the pairwise totals.
> 
> > Mike Ossipoff advised me to forget it, because (having been 
> rebuffed 
> > himself
> > after proposing all of these ideas and more) he had found out 
> by sad 
> > experience
> > that the hard core IRV supporters were too closed minded
> 
> i *know* i loosened a few IRV supporters here in Burlington. 
> but, 
> unfortunately, the "Keep Voting Simple" side that brought us 
> back to 
> Plurality and Delayed Runoff believe that God herself has 
> ordained the 
> vote-for-only-one ballot. we won't be revisiting anything with 
> a 
> ranked ballot again in my lifetime. i hope i'm wrong about that.
> 
> > to even consider
> > anything other than pure Hare/STV/AV/IRV. Since that time I 
> have 
> > found a few
> > staunch IRV supporters that are willing to think about other 
> > possibilities, but
> > on the whole Mike seems to have been right.
> 
> well, when a few more towns toss out IRV, i hope that FairVote 
> gets 
> the message and starts promoting other tabulation methods than 
> STV 
> with the ranked ballot. what makes me so mad is that Burlington 
> 
> people that are IRV supporters (because they are election reform 
> 
> people and do not believe in the two-party religion), these 
> people had 
> no idea that there was another way to look at those very same 
> ballots. Fairvote essentially sold ranked-choice voting with 
> IRV as 
> if they were the same thing. as if there *is* no ranked-choice 
> voting 
> without IRV.
> 
> --
> 
> r b-j rbj at audioimagination.com
> 
> "Imagination is more important than knowledge."
> 
> 
> 
> 
> 
> 
> ------------------------------
> 
> Message: 4
> Date: Thu, 12 May 2011 10:38:48 +0200
> From: Kristofer Munsterhjelm 
> To: robert bristow-johnson 
> Cc: election-methods at lists.electorama.com, fsimmons at pcc.edu
> Subject: Re: [EM] eliminate the plurality loser until there is a
> Condorcet winner
> Message-ID: <4DCB9C98.2000902 at lavabit.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> 
> robert bristow-johnson wrote:
> > 
> > On May 11, 2011, at 3:51 PM, fsimmons at pcc.edu wrote:
> > 
> >>
> >> James Green-Armytage asked
> >>
> >> Quick question for everyone: Do you happen to know when the method
> >> described in the subject line (eliminate the plurality loser until
> >> there is a Condorcet winner) was first proposed?
> > 
> > by Plurality Loser, do you mean the candidate who was ranked 
> 1st the 
> > fewest times or the candidate ranked last the most times (all 
> who are 
> > unranked are tied for last place)?
> 
> The Plurality loser is the one who ranks last (loser) in the ordering
> given by Plurality. Hence, among those that you state, it is the 
> former.Essentially, it is IRV, but at every step, you check if 
> there's a CW
> among the candidates remaining; if there is, that person is 
> elected and
> you're done.
> > 
> > i made mention of either in a paper i wrote in 2009 ("The 
> Failure of 
> > Instant Runoff Voting to accomplish the very purposes for 
> which it was 
> > adopted: An object lesson in Burlington Vermont") right after 
> i figgered 
> > out that the Condorcet winner was not the same as the IRV 
> winner (and 
> > happened to be the candidate i supported).
> > 
> > i would think that this would have preceded by anyone thinking 
> about 
> > Condorcet cycle for a minute.
> 
> Another way of getting a Condorcet compliant runoff method is to 
> do IRV
> with Borda (Nanson's method), or better, eliminate-below-mean-
> scores IRV
> with Borda (Baldwin's method). These methods have actually been 
> used in
> the real political world, which is not something many Condorcet 
> methodscan say, and apparently they also elect from the Smith 
> set. Being runoff
> methods, however, they are not monotone, and I remember reading that
> they're quite manipulable.
> 
> > well, when a few more towns toss out IRV, i hope that FairVote 
> gets the 
> > message and starts promoting other tabulation methods than STV 
> with the 
> > ranked ballot. what makes me so mad is that Burlington people 
> that are 
> > IRV supporters (because they are election reform people and do 
> not 
> > believe in the two-party religion), these people had no idea 
> that there 
> > was another way to look at those very same ballots. Fairvote 
> > essentially sold ranked-choice voting with IRV as if they were 
> the same 
> > thing. as if there *is* no ranked-choice voting without IRV.
> 
> FV didn't swerve in their game of chicken, so to speak. They 
> decided to
> link ranked ballots directly to IRV, presumably so that when 
> people get
> the (commonsense) idea that perhaps ranking would help break the 
> nationout of the two-party stranglehold, they'll immediately 
> think of IRV.
> That strategy does have its benefits from FV's point of view, 
> since it
> makes it more likely that people will pass IRV, but it also is very
> damaging against the ranked ballot concept in general if/when people
> then find IRV not good enough.
> 
> Whether or not they're pursuing IRV for its own sake (and think 
> it's a
> good singlewinner method) or they're doing it to have IRV be a 
> steppingstone to STV, I don't know.
> 
> 
> 
> 
> ------------------------------
> 
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> End of Election-Methods Digest, Vol 83, Issue 14
> ************************************************
>