Kristoffer, just a small P.S. to my email below.
Maybe the problems with the incomplete ballots and dynamic quotas below have something to do with electing a fixed number of seats. That's just a hunch. I think you mentioned that a variable number of seats might give better proportional representation than a fixed number. However electing a variable number of seats will probably have little political support in my party, so this question is more a question out of curiousity. Peter On Fri, May 27, 2011 at 12:28 PM, Peter Zbornik <[email protected]> wrote: > Hi Kristoffer, > > answers in the text of your email below. > > For the Czech Green party, we might get some STV elections (probably > IRV-STV, maybe Meek-STV) for some of the party councils encoded in our > statutes by the end of this year. > > For now, proportional party list elections, ranked proportional council > elections and condorcet based elections seem to be out of the picture for > now, as the interest is too low. > > For information: ranked proportional party lists are used by at least > the Scottish greens, the English greens and the UK Liberals in at least some > elections. > I can send some references to their statutes, in case anybody is > interested. > > STV in green political parties seems to be exclusively used only in > anglo-saxon countries, where it is used rather often. > > Best regards > Peter Zborník > > > On Thu, May 26, 2011 at 8:00 PM, Kristofer Munsterhjelm < > [email protected]> wrote: > > >> Peter Zbornik wrote: >> >> >>> Dear all, >>> Please let me return to an older discussion (see emails below). >>> The issue of the hybrid ballot A>B=C>D. >>> Just an idea on this topic, which might be worth mentioning. >>> It could be a way to handle the problem of bullet voting. >>> Ant it could be a way to disband the dichotomy between different >>> criterias of winning in condorcet elections (margins, winning votes, quotas >>> losing votes). >>> 1] IRV-based elections: >>> Basically in IRV-based STV, when arriving at an equal sign in the ballot, >>> the ballot could simply be split into the number of candidates with equal >>> preferences and re-weighted accordingly (i.e. for instance A=B=C would give >>> three ballots, A>B=C, B>A=C, C>A=B, each with weight 1/3 of the original >>> weight). >>> >>> >> >> This sounds a lot like Woodall's concept of "symmetric completion". A >> method passes symmetric completion if truncated ballots are split into >> ballots with the latter (truncated) preferences filled out, for all possible >> ways those can be filled out, and with the same cumulative power. E.g. with >> candidates A,B,C,D and a method satisfying symmetric completion, >> >> 1: A>B >> >> is the same as >> >> 0.5: A>B>C>D >> 0.5: A>B>D>C. >> >> Unless I'm mistaken, you're generalizing symmetric completion to >> equal-rank. >> >> > > Yes, I am generalizing symmetric completion to equal rank. > Unlike Woodal my proposal is computable for a large number of candidates in > IRV based STV elections. > > If we wanted to perform symmetric completion according to Woodall and if > we would have, say seventeen candidates, who were equal-ranked, then for > each ballot, we would need to generate 17!=355.687.428.096.000 > strictly-ranked ballots in order to exhaust all permutations, which is not > computationally feasible. > > Example an IRV-STV election: A=B=C would according to Woodall be broken > down into 3!=6 ballots: ABC, ACB, BAC, BCA, CAB, CBC. > > I propose that the ballot to be broken down into 3 ballots: A>B=C, B>A=C, > C>A=B, which is nicely computable and the result is the same as Woodalls > proposal for IRV-STV elections. > > Maybe the reason why equally ranked ballots aren't used in STV elections > might be that a computable solution hasn't explicitly been given. > > The issue of a truncated ballot (incomplete ballot or partially blank > ballot) is different from the treatment of equally ranked candidates. > > >> Woodall writes about symmetric completion here: >> http://www.votingmatters.org.uk/ISSUE3/P5.HTM , where he also shows that >> STV does not obey that criterion, but that IRV does. In another Voting >> Matters article (http://www.votingmatters.org.uk/ISSUE14/P1.HTM ), he >> shows how STV can be made to obey symmetric completion, but says that doing >> so isn't a good idea. >> > > It seems that this is a matter of taste. > The authors argue for their criterion based on one example. > I do not find the example convincing, since when adding a candidate with a > large number of additional votes in an STV election, then we have a > different electorate which should be differently proportionally represented. > > After reading the articles above, I've come to think that the issue boils > down to how to handle blank votes. > The issue is not as clear-cut as I thought :o) > > Weather one accepts the plurality criterion really depends on the > preferred treatment of incomplete ballots, or partially blank ballots as I > would rather call them. > > In order to guarantee to get all seats elected in an STV elections, it > seems that four different treatments of partially blank votes are possible: > 1] the symmetrical completion, which is equivalent to requiring all voters > to rank all candidates as Kevin pointed out. > 2] dynamic (or shrinking) quotas based on the number of active votes. > 3] the candidate X: "none of the above" and new election if "none of the > above" is elected (http://en.wikipedia.org/wiki/None_of_the_above) > 4] some seats simply are not elected (using static quotas). A new election > is held for the remaining seats. > > Option three is used in the UK green party and possibly in other green > parties. > Personally I think that the blank vote should be respected, as a protest > vote (this is in a way a very Green political issue, I think) and always be > included in the quota. > > Personally I would probably prefer option 4. The seats, which were not > filled due to the partially blank ballots (i.e. incomplete ballots) would be > filled in a new election. > In the Czech green party, the blank vote is counted as a legitimate vote > and counted into the quora needed to get elected (i.e. if one candidate gets > 45% of the votes the second gets 10% and the rest of the votes are blank, > then new elections are held) > The green party of California is using static quotas. > > The voters, who did not complete their ballots are simply over-run in the > second election, but have the option "to protest". > > I guess I prefer the options in the following order 4>1>2>3 > > What is your preference ordering and why, if different from above :o) > > >> In a more general sense, there are two possible ways to handle equal rank >> in a weighted positional system. I think the first has been called "whole" >> and the second "fractional" on the list - that is at least the names I use >> in Quadelect. >> If the method is "whole" (or ER-, e.g. ER-Plurality), equal ranks give the >> same point value to every candidate that is equal ranked. With ER-Plurality >> you can simulate approval, for instance, by simply voting all approved >> candidates equal first, ahead of all not-approved candidates. >> If the method is "fractional", equal ranks distribute the point score over >> all the candidates equally ranked. Equally ranking k candidates first in >> Plurality would give each 1/k of the ballot's weight, and if I'm not >> mistaken, this is equivalent to generalized symmetric completion. You can >> simulate cumulative voting with fractional Plurality. >> > >> >> >>> Condorcet-based elections: >>> In Condorcet elections (including STV) then A=B would simply mean 0.5 >>> wins for A>B and 0.5 wins for B>A. >>> >>> >> >> That's what Margins does. As a consequence, methods based on Margins can >> meet symmetric completion, but methods based on WV can't. However, Margins >> methods can't meet the Plurality criterion whereas WV can. > > > To paraphrase Woodall, I think that Plurality is "a rather arbitary > property that surely mustn't hold in any real election". > Indeed plurality voting has very little to do with proportional > representation and is in some sense contrary to the idea of proportional > representation. > > To state it differently: my hunch is that for incomplete ballots, dynamic > IRV-STV quotas give a less proportional representation than IRV-STV with > symmetrical completion. > > Could this be tested in your simulator? > Say IRV-STV elections with three or four candidates and incomplete ballots > (say some bullet-voting voters). > Method 1: static quotas and symmetrical completion > Method 2: dynamic quotas and no symmetrical completion > Method 3: static quotas and a new election if the option "none of the > above" is elected > Method 4: IRV-STV with static quotas and no symmetrical complketion and new > elections if all seats are not elected. > Method 5: IRV-STV with static quotas and no symmetrical complketion > and no new elections if all seats are not elected. > The result could be maybe shed some light on this problem. > My hunch is that method 5 gives the most proportional representation. > > I guess the scenario above could be repeated for any STV method (like > Schulze-STV etc). > > I am not at this point able to specify the scenario closer. > Basically it depends on how "proportional representation" is measured. > I have not been following the discussion on this forum and don't remember > if there was ever a continuous "proportionality measure" proposed, but I > remember you worked extensively with the issue. > My appologies for my bad memory. > What measure do you recommend. > > Maybe election 12 in http://www.votingmatters.org.uk/ISSUE3/P5.HTM could > be used as a starting point, as this example is what Woodall seems to base > his argument for the plurality criterion on. > > >> >> >> >>> Kevin Venzke wrote in his mail below (May 9th 2010): >>> >>> >>>> 35 A>B >>>> 25 B >>>> 40 C >>>> A will win. This is only acceptable when you assume that the B and C >>>> voters meant to say that A is just as good as the other candidate that >>>> they didn't rank. I don't think this is likely to be what voters expect. >>>> It seems misleading to even allow truncation as an option if it's >>>> treated >>>> like this. >>>> >>>> >>> End of quote >>> Well I think think that as a voter I would indeed be pleased if A would >>> win and not C. >>> >>> >> >> The example above shows how Margins can fail to meet Plurality. The >> Plurality criterion says that if some voter X has more first place votes >> than Y has *any* place votes, then Y shouldn't win. Yet that's what happens >> above: >> C has 40 first place votes. A has 35 any place votes, yet A wins. Margins >> elects A. Any other method that does, also fails Plurality. >> >> >> > >
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