Toby, According to one definition of a "clone" is that they all get the same rating on a ratings ballot. STAR has ratings ballots that in the final stage it interprets as ranking ballots.  Voters can't make any ranking distinction among candidates they score the same. This would be much less egregious if many many more scores were available, say 0- 10000. The Clone-Loser thing enabling a clone of the score-winner that pairwise loses to the score runner-up to displace the score runner-up out of the final is relatively benign. If we define clones as candidates that are voted together on all ballots with the minimum score distinction needed to make ranking distinction among them, then the method fails Clone-Winner. Frankly I can't see any place for "proportional" anything in single-winner method.  The point of  STAR is that it is very simple so people can understand how it works and on-the-surface seems more-or-less benign and "democratic", and it isn't IRV which is much much better. It isn't something that anyone serious looks at with a view to "improving" it with some relatively complicated kludge. Chris On 21/08/2023 10:20 pm, Toby Pereira wrote: > Chris > > I thought one of your big problems with STAR was the cloning thing. So > the fact that score ballots might jeopardise the clone run-off would > be a good thing wouldn't it? > > Your approval opposition run-off is perhaps similar in outlook to what > I suggested previously about using a sequential proportional method to > elect two candidates to the run-off. Except that I would deal with > clones by allowing a single candidate (or their exact clone depending > on how you want to define it) to win both seats in the run-off. In the > case where single candidate has so much support that they could win > the first two seats in a proportional election, it would be deemed > that no run-off is needed. > > Toby > > On Monday, 21 August 2023 at 13:38:45 BST, C.Benham > <cbenham@adam.com.au> wrote: > > > Toby, > >> Also a run-off between the most two approved candidates still has >> STAR's clone problem. > > Some years ago I suggested that 2-round Top-Two Runoff could be > improved by using approval ballots in the first round > and then having a runoff between the most approved candidate (the AW) > and the candidate with the most approval opposition > to the AW (i.e. is most approved on ballots that don't approve the AW). > >> If the most approved candidate is cloned, the run-off becomes >> irrelevant. >> > Spoken like someone who lives in parliamentist country. "Clones" > aren't necessarily identical.  There could be slight political differences > or one may be less corrupt, or one could just have a much better haircut. > > Parties being having incentive to each field two candidates (even if > they are "clones") is maybe not too bad.  But STAR uses score ballots > so there is a danger that there being two candidates from the same > party might cause voters to not give both of them max score enough > to stop both of them from making the final. > >> However, I just don't think that STAR's failure here can reasonably >> be called a monotonicity failure. > > I think it is very much like one and it's claiming of bragging rights > on that point over IRV is unfair and misleading. > > Chris > >

On Mon, Aug 21, 2023, 5:38 AM C.Benham <cbenham@adam.com.au> wrote: > Toby, > > Also a run-off between the most two approved candidates still has STAR's > clone problem. > > > Some years ago I suggested that 2-round Top-Two Runoff could be improved > by using approval ballots in the first round > and then having a runoff between the most approved candidate (the AW) and > the candidate with the most approval opposition > to the AW (i.e. is most approved on ballots that don't approve the AW). > This is a simpler way of specifying the candidate with the second greatest Transferred Vote Count in Martin Harper's approval vote transfer scheme ... which he invented as a tongue in cheek response to IRV voters' claims that Approval failed "one person, one vote." Here's my generalization of Martin Harper's idea to Score Voting: Suppose that for each candidate X, TS(X) is X's Total Score... the sum over all score ballots B, of B(X), the score assigned to X by B. Then ballot B's (one and only) "transferred vote" should go to the candidate X with the largest product X*B(X). So the analogous score runoff would be between the two candidates with the most transferred votes as determined by this score vote transfer scheme. > > If the most approved candidate is cloned, the run-off becomes irrelevant. > > Spoken like someone who lives in parliamentist country. "Clones" aren't > necessarily identical. There could be slight political differences > or one may be less corrupt, or one could just have a much better haircut. > > Parties being having incentive to each field two candidates (even if they > are "clones") is maybe not too bad. But STAR uses score ballots > so there is a danger that there being two candidates from the same party > might cause voters to not give both of them max score enough > to stop both of them from making the final. > > However, I just don't think that STAR's failure here can reasonably be > called a monotonicity failure. > > I think it is very much like one and it's claiming of bragging rights on > that point over IRV is unfair and misleading. > > Chris > > > > > On 20/08/2023 5:55 am, Toby Pereira wrote: > > Also a run-off between the most two approved candidates still has STAR's > clone problem. If the most approved candidate is cloned, the run-off > becomes irrelevant. > > Toby > > On Saturday, 19 August 2023 at 17:43:12 BST, Toby Pereira > <tdp201b@yahoo.co.uk> <tdp201b@yahoo.co.uk> wrote: > > > Chris > > It's not that I disagree with your views of STAR's behaviour as a method. > And there are changes that could be made that would improve STAR, as you > say. However, I just don't think that STAR's failure here can reasonably be > called a monotonicity failure. > > Toby > > On Saturday, 19 August 2023 at 04:10:32 BST, C.Benham > <cbenham@adam.com.au> <cbenham@adam.com.au> wrote: > > > Toby, > > I wouldn't count this as a monotonicity failure because it involves > decreasing Y's score as well as increasing X's. > > > > This is like a sophist's technical loophole. Why do we particularly care > about "monotonicity failure"? To avoid some hypothetical mild > embarrassment? > For the sake of marketing bragging rights? > > Or because it is related to Push-over strategy incentive/vulnerability? > STAR is much worse in that respect than IRV because there the strategists > are entirely > relying on other voters to both get their favourite into the final two and > to there win the pairwise contest, so if too many of X's supporters try the > strategy it > could backfire. > > Whereas with STAR the strategists could be a bit cautious and give the > weak candidate they are trying to promote into the final a score of max. > minus one > while also giving their favourite X max. points. > > That way all of X's supporters could use the strategy and it could still > succeed. > > The 0-5 score ballot is too restrictive (certainly for STAR) Say, as I > earlier advocated, the voters rank however many candidates they want to and > give an approval cutoff wherever > they want, and we elect the pairwise winner between the two most approved > candidates. > > That would be very similar to STAR (0-5 score ballots) but wouldn't it be > better? And also a method that fails mono-raise and Condorcet and many > other criteria > and is obviously terrible? > > Chris > On 17/08/2023 9:47 pm, Toby Pereira wrote: > > I wouldn't count this as a monotonicity failure because it involves > decreasing Y's score as well as increasing X's. Mono-raise may have been > defined specifically for ordinal ballots where raising a candidate > inevitably pushes others down. Whereas with a rated ballot, I think one > would be more likely to define monotonicity criteria in terms of increasing > a candidate's score while leaving all others the same. > > Toby > > > On Thursday, 17 August 2023 at 05:43:00 BST, C.Benham > <cbenham@adam.com.au> <cbenham@adam.com.au> wrote: > > > Toby Pereira wrote: > > I'm not a fan of STAR, but I am still interested in seeing how it stands > up to scrutiny given that it has a following. (Actually I'm not aware of > how STAR fails monotonicity. I was under the impression that it passed.) > > Toby, > > To give you a bit of a preview before I get around to cooking up all the > examples, nothing with such obvious Push-over incentive can meet mono-raise > (aka "monotonicty") > > Suppose X beats Y in the final. Now suppose on some ballots with Y > above X, we raise X so it is now above Y. That could reduce Y's score > enough for it to be replaced in the final > by Z, a candidate that pairwise beats X. > > Voters who are mainly concerned to have their favourite X win and are > fairly certain that X will reach the final will have a strong incentive to > give X max points (5) and then also > give a 4 (or even a 5) to all those candidates that they think X can beat > pairwise. > > If enough voters use that strategy and it fails, both the finalists could > be candidates with little sincere support. > > Chris Benham > > O > >