On 6/22/2024 1:31 AM, Chris Benham wrote: > I think those of us who are extra hung-up about frustrating Burial > should look more closely at Double Defeat, Hare. ... What is Double Defeat Hare? I didn't try to find it on Electowiki because lately that website has not been responding when I click on links to it. Richard Fobes the VoteFair guy (and now the only Richard here) On 6/22/2024 1:31 AM, Chris Benham wrote: > Kevin, > > Something I didn't address in my previous email: > >>> And what is wrong with your "Improved >>> Condorcet Approval" method ?  I think it would be good using >>> unrestricted ranking ballots with an explicit approval cutoff. >> ICA or C//A (implicit) are not bad. They don't satisfy SFC. In my >> recent simulations >> on frontrunner truncation strategy, C//A is among the best Condorcet >> methods. In >> random elections I am disturbed that ICA and C//A are worse than WV >> methods at >> strong FBC (i.e. what I call compromise incentive). >> >> You've asked me many times about C//A(explicit) and I still think it's >> bad. The >> entire notion of C//A(implicit) being good at deterring burial is >> based on the >> fact that if you use burial to prevent there from being a Condorcet >> winner, then in >> the "cycle resolution" you cannot prefer any candidate to the one you >> raised >> insincerely. >> >> In C//A(explicit), burial only backfires if it actually creates a fake >> CW. Creating >> a fake cycle is never bad for your favorite. > > In these mass public elections the chance that an individual voter's > ballot will be pivotal is negligible. I would think that if the method > is making some attempt to minimise the number of "wasted votes", then > many voters would want to be able to express their full sincere ranking > and also would at least not mind giving their sincere or semi-sincere > approval cutoff. For example in a Hare (aka IRV) election (with > unrestricted strict ranking from the top) I can't imagine it ever > crossing my mind to vote insincerely (and I never have). > > Also I think the method needs to have some justification on the > assumption that the voters are sincere. So if voters complain "Why > aren't I allowed to rank among the candidates I don't approve?" and "How > do we know that the voted CW is really the CW if we have been forced to > truncate our rankings?", we need some answer that isn't just about > "deterring burial".  We could say "Well this is more simple, and it's > not strictly a Condorcet method but rather an Approval-Condorcet hybrid > that is trying to produce a high SU winner" but I expect that a lot of > voters would not be fully satisfied with that answer.  (I wouldn't be.) > > I have become firmer in my support for Double Defeat (explicit) methods > and my favourite of these is Margins-Sorted Approval. Those method allow > voters to rank however many candidates they wish and also give a > approval cutoff, and no candidate that is pairwise-beaten by a more > approved candidate is allowed to win. Much of the time this is by itself > decisive. > > I think those of us who are extra hung-up about frustrating Burial > should look more closely at Double Defeat, Hare.  I suspect that it has > most of the Condorcet efficiency of an actual Condorcet method while > retaining most of the Burial resistance of Hare, while possibly tending > to give higher SU winners than both. > > Chris B. > > On 21/06/2024 9:32 pm, Kevin Venzke wrote: >> Hi Chris, >> >>> On Mono-add-Plump as a weak version of Participation: >>>> Yes but almost all proposals fail Participation, so we will be in a >>>> lot of trouble >>>> if we insist on this kind of thinking. >>> What sort of "trouble"?  I don't see how your conclusion follows from >>> your premise. Why do "almost all proposals fail Participation"?  It >>> isn't because there is anything inherently wrong with "that kind of >>> thinking". It is because it just happens that Participation is very >>> expensive (in terms of other desirable criterion compliances, such as >>> Condorcet).  But in that way Mono-add-Plump is very very cheap (if not >>> free), and some of us are currently "in trouble" due to disregarding >>> "this kind of thinking". >> What I'm saying is that if we pursue criteria in the vein of >> Participation (or >> monotonicity), we cut down the list of methods we can consider, and we >> aren't >> necessarily getting anything of value except that fewer people can >> call the method >> absurd. What I call inherently of value would be things like sincere >> Condorcet >> efficiency or reduced strategic incentives. >> >>> Suppose a mini-bus with a driver is contracted to pick up a group of >>> people and take then on a trip to one of  X, Y or Z  after polling the >>> passengers on their ranking-preferences among these alternative >>> destinations. After the bus is nearly full it is mistakenly assumed that >>> there will be no more passengers and the driver applies some algorithm >>> to the rankings of those present and announces that winning alternative >>> is X. >>> Then it is learned that there are two more passengers to come to fill up >>> the bus.  They do so and the driver says to them  "I've polled all the >>> other passengers and at the moment the winning destination is X. Where >>> would you like to go?" and they reply "X is our first preference and Y >>> wouldn't be too bad and we are very glad we aren't gong to Z". >>> The driver replies "You prefer Y to Z?  In that case the new winning >>> alternative is Y".   Now if these two voters (and perhaps others whose >>> first preference was X) were enlightened election-method experts, they >>> might think "Obviously this fellow's election-method algorithm fails >>> Participation (and presumably Later-no-Harm).  Perhaps it meets >>> Condorcet, which we know is incompatible with both Participation and >>> Later-no-Harm. Perhaps before we showed up there was a top cycle and our >>> Y>Z preferences turned Y into the Condorcet winner. >>> But we know that Condorcet is also incompatible with Later-no-Help so us >>> revealing our second preferences could have just as likely helped us, so >>> I suppose we were just unlucky." >>> Or if they were not experts but charitably minded they might think "I >>> suppose it is possible that this fellow made an honest mistake due to >>> him being thick and us confusing him with too much information". >>> Now replay this scenario except this time the new passengers just say >>> "Great!  We just really want to go to X and we don't know or care about >>> any other destination."  And then the driver says "In that case the >>> winning alternative changes from X to Y". >>> The response could only be that the destination-decider (supposedly >>> purely based on the passengers' stated preferences) is insane (or >>> malevolent, in any case illegitimate)  and that Y is obviously an >>> illegitimate winner. >>> Did you notice a very different vibe from the first case, which was a >>> failure of Participation and  Mono-add-Top but not Mono-add-Plump? >> The difference in vibe is quite similar to your own difference in vibe >> when you >> compare these situations. >> >> In one case, some voters are willing to say "I guess there were other >> considerations >> in play; we were unlucky" but in the other case they won't go there. >> And that's >> fine, that is their right. >> >>> In December 2008 on EM I argued that Schulze's Generalised Majority >>> Criterion is a mistaken standard because the concept is vulnerable to >>> Mono-add-Plump. >> But given their compatibility, isn't that a strange thing to say? >> >>> Your new MDDA 2 method fails the example I gave: >>> 25 A>B >>> 26 B>C >>> 23 C>A >>> 04 C >>> (78 ballots, majority threshold = 40) >>> Implicit approval scores:  C 53,   B 51,  A 48.   No candidate is >>> disqualified due to sub-majority approval. >>> B>C 51-27,   C>A 53-25,   A>B 48-26.     All candidates have a >>> "majority" strength defeat, so it "isn't possible" to disqualify any >>> candidate on that basis.  So, according to the rules of MDDA 2, we elect >>> the most approved candidate, C. >>> Now say we add 22 ballots that plump for C to give: >>> 25 A>B >>> 26 B>C >>> 23 C>A >>> 26 C >>> (100 ballots, majority threshold = 51) >>> Implicit approval scores:  C 75,   B 51,  A 48.   Now A has sub-majority >>> approval and so is disqualified. >>> B>C 51-49,   C>A 75-25,   A>B 48-26.    Now C and A have >>> majority-strength defeats and B doesn't, so (according to the rules of >>> MDDA 2),  A (again) and C are disqualified leaving B as the new winner. >>> The contention that C is the right winner when there were just 78 >>> ballots but when we add 22 ballots that plump (bullet vote) for C the >>> right winner is no longer C is .... completely crazy. >> The voters' behavior had a side effect of strengthening B. All sorts >> of monotonicity >> failures take such an appearance. >> >> And again, there could be differences in severity, e.g. what percent >> of voters think >> a given phenomenon is absurd. But I don't find that very interesting >> because it >> doesn't tell us about the merits of the method. It's basically >> marketability. >> >>>> Well, in an environment where the concept of "median voter" is likely >>>> to be meaningful,... >>> What "environment" is that?  And why is that the environment the one we >>> should primarily focus on? >> One where voter and candidate preferences can be explained by an >> underlying issue >> space. In this case if you could project everyone onto a plane or >> spectrum it would >> be a bit easy to find the median voter and their preferred candidate. >> >> I think this usually describes public elections, but it probably >> wouldn't cover a >> vote on what color is the best, or a vote on what cuisine to have >> delivered. So I >> think we should probably have IIB for those cases. >> >>> I think that is the sort of thinking that >>> leads some people to support Median Ratings methods, which we know are >>> garbage because they fail Dominant Candidate and Irrelevant Ballots >>> Independence, and the voters have a strong incentive to just submit >>> approval ballots (giving the same result as Approval). And it has led >>> you to the absurdity of suggesting a method that fails Mono-add-Plump. >> Not at all, median rating methods aren't motivated by the notion of a >> single median >> voter. There are multiple median voters on different posed questions, >> and that's >> true on a pairwise matrix as well. >> >>> I think for the purposes of properly analysing single-winner election >>> methods and inspiring the invention of  new ones, we can and should do >>> without criteria that refer  to irrelevant ballots dependent "majority" >>> thresholds or pairwise defeats.  Those have almost no positive point >>> aside from marketing. >> You're saying that criteria directly specifying "majority" and not >> something else >> is what lacks positive points aside from marketing? That could be true. >> >>> My suggestion for something as close as possible to Minimal Defense: >>> *If the number of ballots that vote X above bottom and Y no higher than >>> equal-bottom is greater than Y's maximum pairwise support, then Y can't >>> win.* >> I don't hate that. I don't know what you gain from using "max pairwise >> support" >> instead of "votes in total." >> >>> I propose Double Defeat (Implicit) as something that can substitute for >>> the votes-only versions of Minimal Defense and SFC and also Plurality. >>> *Interpreting ranking (or ranking above equal bottom) as approval, no >>> candidate that is pairwise-beaten by a more approved candidate is >>> allowed to win.* >> It's interesting but it doesn't cover SFC. In an SFC failure scenario the >> disqualified candidate might very well have more approval than the >> candidate who >> disqualifies them. The concern is that supporters of the latter gave >> the election >> away. >> >>> That already inspires a simple method suggestion:  DDI,MMM: *Elect the >>> candidate  not disqualified by Double-Defeat (Implicit) that is highest >>> ordered by MinMax(Margins).* >>> What do you think of that? >> I don't like it but it might be fine. >> >>> And what is wrong with your "Improved >>> Condorcet Approval" method ?  I think it would be good using >>> unrestricted ranking ballots with an explicit approval cutoff. >> ICA or C//A (implicit) are not bad. They don't satisfy SFC. In my >> recent simulations >> on frontrunner truncation strategy, C//A is among the best Condorcet >> methods. In >> random elections I am disturbed that ICA and C//A are worse than WV >> methods at >> strong FBC (i.e. what I call compromise incentive). >> >> You've asked me many times about C//A(explicit) and I still think it's >> bad. The >> entire notion of C//A(implicit) being good at deterring burial is >> based on the >> fact that if you use burial to prevent there from being a Condorcet >> winner, then in >> the "cycle resolution" you cannot prefer any candidate to the one you >> raised >> insincerely. >> >> In C//A(explicit), burial only backfires if it actually creates a fake >> CW. Creating >> a fake cycle is never bad for your favorite. >> >> Kevin >> votingmethods.net >> > ---- > Election-Methods mailing list - see https://electorama.com/em for list info

Chris, sorry if I wasn't clear enough with this statement: > An equal-ranking isn’t a way to express indifference (or else equal-ranks > would never happen); it’s a way of pleading the fifth. Learng that a voter > refuses to say whether they prefer Bob or Bill provides an important piece > of information. In the United States, Americans have a constitutional right to refuse to answer any question they're asked by a police officer or other government official. This is guaranteed by the fifth amendment, and is intended to prevent forced confessions. This extends to guilty pleas, and someone who invokes this right is described as "pleading the fifth (amendment)". Someone who pleads the fifth, in response to an accusation of the crime, is saying "I refuse to provide this information, because it might be harmful to me, or because it might ." Here's an example of a realistic situation where this applies. Say we have a paired matchup where Donald Trump defeats Mitt Romney by 36%-29%, because most Republicans prefer Trump. Most Democrats truncate their ballots and refuse to rank either, which might hurt them: if they support Romney, he might defeat the Democratic candidate. In this situation, we have to work out what their opinions are. So, isn't it reasonable to say this isn't a real victory for Trump at all? It's perfectly reasonable—probable, even—that Romney is much more popular than he looks here, and the only reason Trump looks like he beats is because he has a small but extreme base of supporters. Similarly, what if some Alexandria Ocasio-Cortez voters bullet-vote for moral reasons or because they're overconfident in their chances of victory, and don't want to give a win away to a more moderate Democrat? Wouldn't it reasonable to infer that these AOC supporters, despite ranking all the viable candidates equally, *do* actually support Clinton as their second choice? On Mon, Jun 10, 2024 at 4:35 AM Chris Benham <cbenhamau@yahoo.com.au> wrote: > CLC, > > I assume no-one posts a ballot "intending to be irrelevant" (and whether > they do or not I don't see as relevant). > > Normally I wouldn't expect irrelevant ballots to be literally "empty", > just containing no information about any of the remotely viable information. > > An equal-ranking isn’t a way to express indifference (or else equal-ranks > would never happen); it’s a way of pleading the fifth > > > What? > > Learning that a voter refuses to say whether they prefer Bob or Bill > provides an important piece of information. > > Which is? > > Learning a voter has cast a completely blank ballot is an extreme case, > where the ballot provides a very important piece of information: it means > the voter expects a participation failure, because a nonempty ballot will > hurt them. > > > But an empty one might "help" them ?? Hilarious. > > A rational response to this is to raise the threshold for a defeat, > because setting the bar for a defeat closer to 50% prevents cycles (and > therefore participation failures). In other words, these ballots are > *very* relevant. > > > Of course, you anonymous STAR Voting advocate. > > Chris B. > > On 7/06/2024 1:33 am, Closed Limelike Curves wrote: > > Yeah, MAMPO seems like it might behave more sensibly there. > > IIB doesn’t make sense to me outside of positional voting systems (which > trivially satisfy it). If an empty ballot was genuinely intended to be > irrelevant, the voter wouldn’t have cast it in the first place. An > equal-ranking isn’t a way to express indifference (or else equal-ranks > would never happen); it’s a way of pleading the fifth. Learning that a > voter refuses to say whether they prefer Bob or Bill provides an important > piece of information. > > Learning a voter has cast a completely blank ballot is an extreme case, > where the ballot provides a very important piece of information: it means > the voter expects a participation failure, because a nonempty ballot will > hurt them. > > A rational response to this is to raise the threshold for a defeat, > because setting the bar for a defeat closer to 50% prevents cycles (and > therefore participation failures). In other words, these ballots are > *very* relevant. > > On Thu, Jun 6, 2024 at 7:40 AM Chris Benham <cbenhamau@yahoo.com.au> > wrote: > >> Kevin, >> >> I would not like to see SFC as totally obsolete, since it was one of the motivating >> criteria (along with MD and weak FBC) for my methods MDDA and MAMPO :) >> >> >> Inventing those methods was some achievement as a thought experiment to >> demonstrate that certain criteria are mutually compatible. >> >> But MDDA spectacularly fails the maximum-absurdity criterion >> Mono-add-Plump, a very interesting fact that isn't mentioned on its >> electowiki page. >> >> https://electowiki.org/wiki/Majority_Defeat_Disqualification_Approval >> >> Procedure >> >> The voter submits a ranking of the candidates. The candidates explicitly >> ranked are considered *approved* by that voter. >> >> A candidate is *dominated* if more than half of the voters rank some >> other candidate strictly above him. >> >> All dominated candidates are eliminated, unless this would eliminate all >> the candidates. >> >> Of remaining candidates, the one approved by the most voters is elected. >> Criteria >> >> *MDDA* satisfies the Favorite Betrayal criterion >> <https://electowiki.org/wiki/Favorite_Betrayal_criterion>, Strategy-Free >> criterion <https://electowiki.org/wiki/Strategy-Free_criterion>, the Strong >> Defensive Strategy criterion >> <https://electowiki.org/wiki/Strong_Defensive_Strategy_criterion> (and Minimal >> Defense criterion <https://electowiki.org/wiki/Minimal_Defense_criterion>), >> and monotonicity <https://electowiki.org/wiki/Monotonicity_criterion>. >> >> It fails Clone-Winner <https://electowiki.org/wiki/Strategic_nomination>, >> the Plurality criterion <https://electowiki.org/wiki/Plurality_criterion>, >> the Generalized Strategy-Free criterion >> <https://electowiki.org/wiki/Generalized_Strategy-Free_criterion>, the Condorcet >> criterion <https://electowiki.org/wiki/Condorcet_criterion>, the Smith >> criterion <https://electowiki.org/wiki/Smith_set>, Participation >> <https://electowiki.org/wiki/Participation_criterion>, the Majority >> criterion for solid coalitions >> <https://electowiki.org/wiki/Majority_criterion>, and Later-no-harm >> <https://electowiki.org/wiki/Later-no-harm_criterion>. >> >> >> 25: A>B >> 26: B>C >> 23: C>A >> 04: C >> >> 78 ballots (majority threshold = 40) >> >> B>C 51-27, C>A 53-25, A>B 48-26. Implicit Approval scores: C 53, B 51, A 48. >> >> All the candidates have a majority-strength defeat, so none are eliminated and the most approved candidate, C, wins. >> >> Say we now add 22 ballots that all plump (i.e. bullet vote) for C: >> >> 25: A>B >> 26: B>C >> 23: C>A >> 26: C >> >> 100 ballots (majority threshold = 51) >> >> B>C 51-49, C>A 75-25, A>B 48-26. Implicit Approval scores: C 75, B 51, A 48. >> >> Now only B is without a "majority-strength defeat", so the winner changes from C to B. >> >> Of course the method also fails Irrelevant Ballots Independence. If we now add 3 ballots that plump for X, the majority threshold rises to 52 and so C's majority-strength defeat goes away and C wins again by being the most approved candidate. >> >> This demonstration of Mono-add-Plump failure doesn't apply to MAMPO, but that method would also fail Irrelevant Ballots Independence. It may be far less bad. >> https://electowiki.org/wiki/Majority_Approval,_Minimum_Pairwise_Opposition >> >> Procedure >> >> The voter submits a ranking of the candidates. The candidates explicitly ranked are considered *approved* by that voter. >> >> The *score* for candidate *X* against candidate *Y* is equal to the number of voters ranking *X* above *Y*. The *max score* of candidate *X* is the largest score of any other candidate against *X*. >> >> If nobody is approved by more than half of the voters, then the candidate approved by the most voters is elected. >> >> Otherwise, the candidate with the lowest max score, who is approved by more than half of the voters, is elected. >> >> >> Chris B. >> >> >> >> On 2/06/2024 7:23 am, Kevin Venzke wrote: >> >> Hi all, >> >> When I test for SFC compliance the rule on cast votes is that if there is no >> majority over A, and A has a majority over B, then B can't win. >> >> This is kind of a flip side of MD / SDSC because, if you were forced to explain MD >> in terms of a graph of majority-strength defeats, it would say that if A has a >> majority over B and B doesn't have a majority over anyone, then B can't win. >> >> MD basically says that if there are two frontrunners and everyone truncates their >> less liked frontrunner, then the worse frontrunner won't win. If this property >> doesn't hold, it means the majority has done something to stop the method from >> "seeing" their majority, which is surely that they ranked other candidates above >> the preferred frontrunner. So MD is mostly about compromise incentive. >> >> SFC is probably going to be about truncation. When a method fails it, most likely >> it's because the majority gave the election away to a less liked compromise choice. >> For example: >> >> 20 C>A>B >> 35 A>B >> 5 B >> 40 D >> >> Here B is the implicit approval winner, but by SFC B should not win, because it >> means it was not safe for the A voters to rank B. >> >> I would not like to see SFC as totally obsolete, since it was one of the motivating >> criteria (along with MD and weak FBC) for my methods MDDA and MAMPO :) >> >> Kevinvotingmethods.net >> >>

*or because it might violate my privacy." (Sorry for the incomplete sentence.) On Sat, Jun 22, 2024 at 3:31 PM Closed Limelike Curves < closed.limelike.curves@gmail.com> wrote: > Chris, sorry if I wasn't clear enough with this statement: > >> An equal-ranking isn’t a way to express indifference (or else equal-ranks >> would never happen); it’s a way of pleading the fifth. Learng that a voter >> refuses to say whether they prefer Bob or Bill provides an important piece >> of information. > > In the United States, Americans have a constitutional right to refuse to > answer any question they're asked by a police officer or other government > official. This is guaranteed by the fifth amendment, and is intended to > prevent forced confessions. This extends to guilty pleas, and someone who > invokes this right is described as "pleading the fifth (amendment)". > > Someone who pleads the fifth, in response to an accusation of the crime, > is saying "I refuse to provide this information, because it might be > harmful to me, or because it might ." > > Here's an example of a realistic situation where this applies. Say we have > a paired matchup where Donald Trump defeats Mitt Romney by 36%-29%, because > most Republicans prefer Trump. Most Democrats truncate their ballots and > refuse to rank either, which might hurt them: if they support Romney, he > might defeat the Democratic candidate. > > In this situation, we have to work out what their opinions are. So, isn't > it reasonable to say this isn't a real victory for Trump at all? It's > perfectly reasonable—probable, even—that Romney is much more popular than > he looks here, and the only reason Trump looks like he beats is because he > has a small but extreme base of supporters. Similarly, what if some > Alexandria Ocasio-Cortez voters bullet-vote for moral reasons or because > they're overconfident in their chances of victory, and don't want to give a > win away to a more moderate Democrat? Wouldn't it reasonable to infer that > these AOC supporters, despite ranking all the viable candidates equally, > *do* actually support Clinton as their second choice? > > On Mon, Jun 10, 2024 at 4:35 AM Chris Benham <cbenhamau@yahoo.com.au> > wrote: > >> CLC, >> >> I assume no-one posts a ballot "intending to be irrelevant" (and whether >> they do or not I don't see as relevant). >> >> Normally I wouldn't expect irrelevant ballots to be literally "empty", >> just containing no information about any of the remotely viable information. >> >> An equal-ranking isn’t a way to express indifference (or else equal-ranks >> would never happen); it’s a way of pleading the fifth >> >> >> What? >> >> Learning that a voter refuses to say whether they prefer Bob or Bill >> provides an important piece of information. >> >> Which is? >> >> Learning a voter has cast a completely blank ballot is an extreme case, >> where the ballot provides a very important piece of information: it means >> the voter expects a participation failure, because a nonempty ballot >> will hurt them. >> >> >> But an empty one might "help" them ?? Hilarious. >> >> A rational response to this is to raise the threshold for a defeat, >> because setting the bar for a defeat closer to 50% prevents cycles (and >> therefore participation failures). In other words, these ballots are >> *very* relevant. >> >> >> Of course, you anonymous STAR Voting advocate. >> >> Chris B. >> >> On 7/06/2024 1:33 am, Closed Limelike Curves wrote: >> >> Yeah, MAMPO seems like it might behave more sensibly there. >> >> IIB doesn’t make sense to me outside of positional voting systems (which >> trivially satisfy it). If an empty ballot was genuinely intended to be >> irrelevant, the voter wouldn’t have cast it in the first place. An >> equal-ranking isn’t a way to express indifference (or else equal-ranks >> would never happen); it’s a way of pleading the fifth. Learning that a >> voter refuses to say whether they prefer Bob or Bill provides an important >> piece of information. >> >> Learning a voter has cast a completely blank ballot is an extreme case, >> where the ballot provides a very important piece of information: it means >> the voter expects a participation failure, because a nonempty ballot >> will hurt them. >> >> A rational response to this is to raise the threshold for a defeat, >> because setting the bar for a defeat closer to 50% prevents cycles (and >> therefore participation failures). In other words, these ballots are >> *very* relevant. >> >> On Thu, Jun 6, 2024 at 7:40 AM Chris Benham <cbenhamau@yahoo.com.au> >> wrote: >> >>> Kevin, >>> >>> I would not like to see SFC as totally obsolete, since it was one of the motivating >>> criteria (along with MD and weak FBC) for my methods MDDA and MAMPO :) >>> >>> >>> Inventing those methods was some achievement as a thought experiment to >>> demonstrate that certain criteria are mutually compatible. >>> >>> But MDDA spectacularly fails the maximum-absurdity criterion >>> Mono-add-Plump, a very interesting fact that isn't mentioned on its >>> electowiki page. >>> >>> https://electowiki.org/wiki/Majority_Defeat_Disqualification_Approval >>> >>> Procedure >>> >>> The voter submits a ranking of the candidates. The candidates explicitly >>> ranked are considered *approved* by that voter. >>> >>> A candidate is *dominated* if more than half of the voters rank some >>> other candidate strictly above him. >>> >>> All dominated candidates are eliminated, unless this would eliminate all >>> the candidates. >>> >>> Of remaining candidates, the one approved by the most voters is elected. >>> Criteria >>> >>> *MDDA* satisfies the Favorite Betrayal criterion >>> <https://electowiki.org/wiki/Favorite_Betrayal_criterion>, Strategy-Free >>> criterion <https://electowiki.org/wiki/Strategy-Free_criterion>, the Strong >>> Defensive Strategy criterion >>> <https://electowiki.org/wiki/Strong_Defensive_Strategy_criterion> (and Minimal >>> Defense criterion >>> <https://electowiki.org/wiki/Minimal_Defense_criterion>), and >>> monotonicity <https://electowiki.org/wiki/Monotonicity_criterion>. >>> >>> It fails Clone-Winner <https://electowiki.org/wiki/Strategic_nomination>, >>> the Plurality criterion >>> <https://electowiki.org/wiki/Plurality_criterion>, the Generalized >>> Strategy-Free criterion >>> <https://electowiki.org/wiki/Generalized_Strategy-Free_criterion>, the Condorcet >>> criterion <https://electowiki.org/wiki/Condorcet_criterion>, the Smith >>> criterion <https://electowiki.org/wiki/Smith_set>, Participation >>> <https://electowiki.org/wiki/Participation_criterion>, the Majority >>> criterion for solid coalitions >>> <https://electowiki.org/wiki/Majority_criterion>, and Later-no-harm >>> <https://electowiki.org/wiki/Later-no-harm_criterion>. >>> >>> >>> 25: A>B >>> 26: B>C >>> 23: C>A >>> 04: C >>> >>> 78 ballots (majority threshold = 40) >>> >>> B>C 51-27, C>A 53-25, A>B 48-26. Implicit Approval scores: C 53, B 51, A 48. >>> >>> All the candidates have a majority-strength defeat, so none are eliminated and the most approved candidate, C, wins. >>> >>> Say we now add 22 ballots that all plump (i.e. bullet vote) for C: >>> >>> 25: A>B >>> 26: B>C >>> 23: C>A >>> 26: C >>> >>> 100 ballots (majority threshold = 51) >>> >>> B>C 51-49, C>A 75-25, A>B 48-26. Implicit Approval scores: C 75, B 51, A 48. >>> >>> Now only B is without a "majority-strength defeat", so the winner changes from C to B. >>> >>> Of course the method also fails Irrelevant Ballots Independence. If we now add 3 ballots that plump for X, the majority threshold rises to 52 and so C's majority-strength defeat goes away and C wins again by being the most approved candidate. >>> >>> This demonstration of Mono-add-Plump failure doesn't apply to MAMPO, but that method would also fail Irrelevant Ballots Independence. It may be far less bad. >>> https://electowiki.org/wiki/Majority_Approval,_Minimum_Pairwise_Opposition >>> >>> Procedure >>> >>> The voter submits a ranking of the candidates. The candidates explicitly ranked are considered *approved* by that voter. >>> >>> The *score* for candidate *X* against candidate *Y* is equal to the number of voters ranking *X* above *Y*. The *max score* of candidate *X* is the largest score of any other candidate against *X*. >>> >>> If nobody is approved by more than half of the voters, then the candidate approved by the most voters is elected. >>> >>> Otherwise, the candidate with the lowest max score, who is approved by more than half of the voters, is elected. >>> >>> >>> Chris B. >>> >>> >>> >>> On 2/06/2024 7:23 am, Kevin Venzke wrote: >>> >>> Hi all, >>> >>> When I test for SFC compliance the rule on cast votes is that if there is no >>> majority over A, and A has a majority over B, then B can't win. >>> >>> This is kind of a flip side of MD / SDSC because, if you were forced to explain MD >>> in terms of a graph of majority-strength defeats, it would say that if A has a >>> majority over B and B doesn't have a majority over anyone, then B can't win. >>> >>> MD basically says that if there are two frontrunners and everyone truncates their >>> less liked frontrunner, then the worse frontrunner won't win. If this property >>> doesn't hold, it means the majority has done something to stop the method from >>> "seeing" their majority, which is surely that they ranked other candidates above >>> the preferred frontrunner. So MD is mostly about compromise incentive. >>> >>> SFC is probably going to be about truncation. When a method fails it, most likely >>> it's because the majority gave the election away to a less liked compromise choice. >>> For example: >>> >>> 20 C>A>B >>> 35 A>B >>> 5 B >>> 40 D >>> >>> Here B is the implicit approval winner, but by SFC B should not win, because it >>> means it was not safe for the A voters to rank B. >>> >>> I would not like to see SFC as totally obsolete, since it was one of the motivating >>> criteria (along with MD and weak FBC) for my methods MDDA and MAMPO :) >>> >>> Kevinvotingmethods.net >>> >>>

 An equal-ranking isn’t a way to express indifference (or else
 equal-ranks would never happen); it’s a way of pleading the fifth.
 Learng that a voter refuses to say whether they prefer Bob or Bill
 provides an important piece of information.

 CLC,

 I assume no-one posts a ballot "intending to be irrelevant"  (and
 whether they do or not I don't see as relevant).

 Normally I wouldn't expect irrelevant ballots to be literally
 "empty", just containing no information about any of the remotely
 viable information.

 An equal-ranking isn’t a way to express indifference (or else
 equal-ranks would never happen); it’s a way of pleading the fifth

 What?

 Learning that a voter refuses to say whether they prefer Bob or
 Bill provides an important piece of information.

 Which is?

 Learning a voter has cast a completely blank ballot is an extreme
 case, where the ballot provides a very important piece of
 information: it means the voter expects a participation failure,
 because a nonempty ballot will hurt them.

 But an empty one might "help" them ??  Hilarious.

 A rational response to this is to raise the threshold for a
 defeat, because setting the bar for a defeat closer to 50%
 prevents cycles (and therefore participation failures). In other
 words, these ballots are /very/ relevant.

 Of course, you anonymous STAR Voting advocate.

 Chris B.

 On 7/06/2024 1:33 am, Closed Limelike Curves wrote:

 Yeah, MAMPO seems like it might behave more sensibly there.

 IIB doesn’t make sense to me outside of positional voting systems
 (which trivially satisfy it). If an empty ballot was genuinely
 intended to be irrelevant, the voter wouldn’t have cast it in the
 first place. An equal-ranking isn’t a way to express indifference
 (or else equal-ranks would never happen); it’s a way of pleading
 the fifth. Learning that a voter refuses to say whether they
 prefer Bob or Bill provides an important piece of information.

 Learning a voter has cast a completely blank ballot is an extreme
 case, where the ballot provides a very important piece of
 information: it means the voter expects a participation failure,
 because a nonempty ballot will hurt them.

 A rational response to this is to raise the threshold for a
 defeat, because setting the bar for a defeat closer to 50%
 prevents cycles (and therefore participation failures). In other
 words, these ballots are /very/ relevant.

 On Thu, Jun 6, 2024 at 7:40 AM Chris Benham
 <cbenhamau@yahoo.com.au> wrote:

     Kevin,

     I would not like to see SFC as totally obsolete, since it was one of the motivating
     criteria (along with MD and weak FBC) for my methods MDDA and MAMPO :)

     Inventing those methods was some achievement as a thought
     experiment to demonstrate that certain criteria are mutually
     compatible.

     But MDDA spectacularly fails the maximum-absurdity criterion
     Mono-add-Plump, a very interesting fact that isn't mentioned
     on its electowiki page.

     https://electowiki.org/wiki/Majority_Defeat_Disqualification_Approval

         Procedure

     The voter submits a ranking of the candidates. The
     candidates explicitly ranked are considered/approved/by that
     voter.

     A candidate is/dominated/if more than half of the voters
     rank some other candidate strictly above him.

     All dominated candidates are eliminated, unless this would
     eliminate all the candidates.

     Of remaining candidates, the one approved by the most voters
     is elected.


         Criteria

     *MDDA*satisfies theFavorite Betrayal criterion
     <https://electowiki.org/wiki/Favorite_Betrayal_criterion>,Strategy-Free
     criterion
     <https://electowiki.org/wiki/Strategy-Free_criterion>,
     theStrong Defensive Strategy criterion
     <https://electowiki.org/wiki/Strong_Defensive_Strategy_criterion>(andMinimal
     Defense criterion
     <https://electowiki.org/wiki/Minimal_Defense_criterion>),
     andmonotonicity
     <https://electowiki.org/wiki/Monotonicity_criterion>.

     It failsClone-Winner
     <https://electowiki.org/wiki/Strategic_nomination>,
     thePlurality criterion
     <https://electowiki.org/wiki/Plurality_criterion>,
     theGeneralized Strategy-Free criterion
     <https://electowiki.org/wiki/Generalized_Strategy-Free_criterion>,
     theCondorcet criterion
     <https://electowiki.org/wiki/Condorcet_criterion>, theSmith
     criterion
     <https://electowiki.org/wiki/Smith_set>,Participation
     <https://electowiki.org/wiki/Participation_criterion>,
     theMajority criterion for solid coalitions
     <https://electowiki.org/wiki/Majority_criterion>,
     andLater-no-harm
     <https://electowiki.org/wiki/Later-no-harm_criterion>.

     25: A>B
     26: B>C
     23: C>A
     04: C

     78 ballots (majority threshold = 40)

     B>C 51-27,   C>A 53-25,   A>B 48-26.  Implicit Approval scores: C 53,  B 51, A 48.

     All the candidates have a majority-strength defeat, so none are eliminated and the most approved candidate, C, wins.

     Say we now add 22 ballots that all plump (i.e. bullet vote) for C:

     25: A>B
     26: B>C
     23: C>A
     26: C

     100 ballots (majority threshold = 51)

     B>C 51-49,   C>A 75-25,   A>B 48-26.  Implicit Approval scores: C 75,  B 51, A 48.

     Now only B is without a "majority-strength defeat", so the winner changes from C to B.

     Of course the method also fails Irrelevant Ballots Independence. If we now add 3 ballots that plump for X, the majority threshold rises to 52 and so C's majority-strength defeat goes away and C wins again by being the most approved candidate.

     This demonstration of Mono-add-Plump failure doesn't apply to MAMPO, but that method would also fail Irrelevant Ballots Independence. It may be far less bad.

     https://electowiki.org/wiki/Majority_Approval,_Minimum_Pairwise_Opposition

         Procedure

     The voter submits a ranking of the candidates. The
     candidates explicitly ranked are considered/approved/by that
     voter.

     The/score/for candidate/X/against candidate/Y/is equal to
     the number of voters ranking/X/above/Y/. The/max score/of
     candidate/X/is the largest score of any other candidate
     against/X/.

     If nobody is approved by more than half of the voters, then
     the candidate approved by the most voters is elected.

     Otherwise, the candidate with the lowest max score, who is
     approved by more than half of the voters, is elected.

     Chris B.



     On 2/06/2024 7:23 am, Kevin Venzke wrote:

     Hi all,

     When I test for SFC compliance the rule on cast votes is that if there is no
     majority over A, and A has a majority over B, then B can't win.

     This is kind of a flip side of MD / SDSC because, if you were forced to explain MD
     in terms of a graph of majority-strength defeats, it would say that if A has a
     majority over B and B doesn't have a majority over anyone, then B can't win.

     MD basically says that if there are two frontrunners and everyone truncates their
     less liked frontrunner, then the worse frontrunner won't win. If this property
     doesn't hold, it means the majority has done something to stop the method from
     "seeing" their majority, which is surely that they ranked other candidates above
     the preferred frontrunner. So MD is mostly about compromise incentive.

     SFC is probably going to be about truncation. When a method fails it, most likely
     it's because the majority gave the election away to a less liked compromise choice.
     For example:

     20 C>A>B
     35 A>B
     5 B
     40 D

     Here B is the implicit approval winner, but by SFC B should not win, because it
     means it was not safe for the A voters to rank B.

     I would not like to see SFC as totally obsolete, since it was one of the motivating
     criteria (along with MD and weak FBC) for my methods MDDA and MAMPO :)

     Kevin
     votingmethods.net  <http://votingmethods.net>

CLC, > An equal-ranking isn’t a way to express indifference.. Of course that is exactly what it is. > ...(or else equal-ranks would never happen) .. (For this email I'll refrain from subtle sarcasm.) That doesn't make any sense. > Learning that a voter refuses to say whether they prefer Bob or Bill > provides an important piece of information. I can't imagine what that might be if it was the case, but we haven't "learn't" any such thing.  The voter hasn't expressed a preference between Bob and Bill.  Sans mind-reading technology I don't see that we have any choice other than following the Occam's Razor principle and assume the voter has no preference between Bob and Bill. > Here's an example of a realistic situation where this applies. Say we > have a paired matchup where Donald Trump defeats Mitt Romney by > 36%-29%, because most Republicans prefer Trump. Most Democrats > truncate their ballots and refuse to rank either, which might hurt > them: if they support Romney, he might defeat the Democratic candidate. > > In this situation, we have to work out what theiropinions are. I don't see why.  And how?  And who exactly is this "we"? > So, isn't it reasonable to say this isn't a real victory for Trump at > all? No, it is not reasonable. > It's perfectly reasonable—probable, even—that Romney is much more > popular than he looks here, and the only reason Trump looks like he > beats is because he has a small but extreme base of supporters. It may or may not be an accurate guess, but I can't see anything "reasonable" about it. > Similarly, what if some Alexandria Ocasio-Cortez voters bullet-vote > for moral reasons or because they're overconfident in their chances of > victory, and don't want to give a win away to a more moderate > Democrat? Wouldn't it reasonable to infer that these AOC supporters, > despite ranking all the viable candidates equally, /do/actually > support Clinton as their second choice? Same answer: No. There is more than  one way to define "popular".  And the incentives of the method are obviously a big factor in our guessing about how well the ballots reflect the voters' sincere preferences. Chris B. On 23/06/2024 8:01 am, Closed Limelike Curves wrote: > Chris, sorry if I wasn't clear enough with this statement: > > An equal-ranking isn’t a way to express indifference (or else > equal-ranks would never happen); it’s a way of pleading the fifth. > Learng that a voter refuses to say whether they prefer Bob or Bill > provides an important piece of information. > > In the United States, Americans have a constitutional right to refuse > to answer any question they're asked by a police officer or other > government official. This is guaranteed by the fifth amendment, and is > intended to prevent forced confessions. This extends to guilty pleas, > and someone who invokes this right is described as "pleading the fifth > (amendment)". > > Someone who pleads the fifth, in response to an accusation of the > crime, is saying "I refuse to provide this information, because it > might be harmful to me, or because it might violate my privacy  ." > > Here's an example of a realistic situation where this applies. Say we > have a paired matchup where Donald Trump defeats Mitt Romney by > 36%-29%, because most Republicans prefer Trump. Most Democrats > truncate their ballots and refuse to rank either, which might hurt > them: if they support Romney, he might defeat the Democratic candidate. > > In this situation, we have to work out what theiropinions are. So, > isn't it reasonable to say this isn't a real victory for Trump at all? > It's perfectly reasonable—probable, even—that Romney is much more > popular than he looks here, and the only reason Trump looks like he > beats is because he has a small but extreme base of supporters. > Similarly, what if some Alexandria Ocasio-Cortez voters bullet-vote > for moral reasons or because they're overconfident in their chances of > victory, and don't want to give a win away to a more moderate > Democrat? Wouldn't it reasonable to infer that these AOC supporters, > despite ranking all the viable candidates equally, /do/actually > support Clinton as their second choice? > > > On Mon, Jun 10, 2024 at 4:35 AM Chris Benham <cbenhamau@yahoo.com.au> > wrote: > > CLC, > > I assume no-one posts a ballot "intending to be irrelevant"  (and > whether they do or not I don't see as relevant). > > Normally I wouldn't expect irrelevant ballots to be literally > "empty", just containing no information about any of the remotely > viable information. > >> An equal-ranking isn’t a way to express indifference (or else >> equal-ranks would never happen); it’s a way of pleading the fifth > > What? > >> Learning that a voter refuses to say whether they prefer Bob or >> Bill provides an important piece of information. >> > Which is? > >> Learning a voter has cast a completely blank ballot is an extreme >> case, where the ballot provides a very important piece of >> information: it means the voter expects a participation failure, >> because a nonempty ballot will hurt them. > > But an empty one might "help" them ??  Hilarious. > >> A rational response to this is to raise the threshold for a >> defeat, because setting the bar for a defeat closer to 50% >> prevents cycles (and therefore participation failures). In other >> words, these ballots are /very/ relevant. > > Of course, you anonymous STAR Voting advocate. > > Chris B. > > On 7/06/2024 1:33 am, Closed Limelike Curves wrote: >> Yeah, MAMPO seems like it might behave more sensibly there. >> >> IIB doesn’t make sense to me outside of positional voting systems >> (which trivially satisfy it). If an empty ballot was genuinely >> intended to be irrelevant, the voter wouldn’t have cast it in the >> first place. An equal-ranking isn’t a way to express indifference >> (or else equal-ranks would never happen); it’s a way of pleading >> the fifth. Learning that a voter refuses to say whether they >> prefer Bob or Bill provides an important piece of information. >> >> Learning a voter has cast a completely blank ballot is an extreme >> case, where the ballot provides a very important piece of >> information: it means the voter expects a participation failure, >> because a nonempty ballot will hurt them. >> >> A rational response to this is to raise the threshold for a >> defeat, because setting the bar for a defeat closer to 50% >> prevents cycles (and therefore participation failures). In other >> words, these ballots are /very/ relevant. >> >> On Thu, Jun 6, 2024 at 7:40 AM Chris Benham >> <cbenhamau@yahoo.com.au> wrote: >> >> Kevin, >> >>> I would not like to see SFC as totally obsolete, since it was one of the motivating >>> criteria (along with MD and weak FBC) for my methods MDDA and MAMPO :) >> >> Inventing those methods was some achievement as a thought >> experiment to demonstrate that certain criteria are mutually >> compatible. >> >> But MDDA spectacularly fails the maximum-absurdity criterion >> Mono-add-Plump, a very interesting fact that isn't mentioned >> on its electowiki page. >> >> https://electowiki.org/wiki/Majority_Defeat_Disqualification_Approval >>> >>> >>> Procedure >>> >>> The voter submits a ranking of the candidates. The >>> candidates explicitly ranked are considered/approved/by that >>> voter. >>> >>> A candidate is/dominated/if more than half of the voters >>> rank some other candidate strictly above him. >>> >>> All dominated candidates are eliminated, unless this would >>> eliminate all the candidates. >>> >>> Of remaining candidates, the one approved by the most voters >>> is elected. >>> >>> >>> Criteria >>> >>> *MDDA*satisfies theFavorite Betrayal criterion >>> <https://electowiki.org/wiki/Favorite_Betrayal_criterion>,Strategy-Free >>> criterion >>> <https://electowiki.org/wiki/Strategy-Free_criterion>, >>> theStrong Defensive Strategy criterion >>> <https://electowiki.org/wiki/Strong_Defensive_Strategy_criterion>(andMinimal >>> Defense criterion >>> <https://electowiki.org/wiki/Minimal_Defense_criterion>), >>> andmonotonicity >>> <https://electowiki.org/wiki/Monotonicity_criterion>. >>> >>> It failsClone-Winner >>> <https://electowiki.org/wiki/Strategic_nomination>, >>> thePlurality criterion >>> <https://electowiki.org/wiki/Plurality_criterion>, >>> theGeneralized Strategy-Free criterion >>> <https://electowiki.org/wiki/Generalized_Strategy-Free_criterion>, >>> theCondorcet criterion >>> <https://electowiki.org/wiki/Condorcet_criterion>, theSmith >>> criterion >>> <https://electowiki.org/wiki/Smith_set>,Participation >>> <https://electowiki.org/wiki/Participation_criterion>, >>> theMajority criterion for solid coalitions >>> <https://electowiki.org/wiki/Majority_criterion>, >>> andLater-no-harm >>> <https://electowiki.org/wiki/Later-no-harm_criterion>. >>> >>> >> >> 25: A>B >> 26: B>C >> 23: C>A >> 04: C >> >> 78 ballots (majority threshold = 40) >> >> B>C 51-27,   C>A 53-25,   A>B 48-26. Implicit Approval scores: C 53, B 51, A 48. >> >> All the candidates have a majority-strength defeat, so none are eliminated and the most approved candidate, C, wins. >> >> Say we now add 22 ballots that all plump (i.e. bullet vote) for C: >> >> 25: A>B >> 26: B>C >> 23: C>A >> 26: C >> >> 100 ballots (majority threshold = 51) >> >> B>C 51-49,   C>A 75-25,   A>B 48-26. Implicit Approval scores: C 75, B 51, A 48. >> >> Now only B is without a "majority-strength defeat", so the winner changes from C to B. >> >> Of course the method also fails Irrelevant Ballots Independence. If we now add 3 ballots that plump for X, the majority threshold rises to 52 and so C's majority-strength defeat goes away and C wins again by being the most approved candidate. >> >> This demonstration of Mono-add-Plump failure doesn't apply to MAMPO, but that method would also fail Irrelevant Ballots Independence. It may be far less bad. >> >> https://electowiki.org/wiki/Majority_Approval,_Minimum_Pairwise_Opposition >> >>> >>> Procedure >>> >>> The voter submits a ranking of the candidates. The >>> candidates explicitly ranked are considered/approved/by that >>> voter. >>> >>> The/score/for candidate/X/against candidate/Y/is equal to >>> the number of voters ranking/X/above/Y/. The/max score/of >>> candidate/X/is the largest score of any other candidate >>> against/X/. >>> >>> If nobody is approved by more than half of the voters, then >>> the candidate approved by the most voters is elected. >>> >>> Otherwise, the candidate with the lowest max score, who is >>> approved by more than half of the voters, is elected. >>> >> >> Chris B. >> >> >> >> On 2/06/2024 7:23 am, Kevin Venzke wrote: >>> Hi all, >>> >>> When I test for SFC compliance the rule on cast votes is that if there is no >>> majority over A, and A has a majority over B, then B can't win. >>> >>> This is kind of a flip side of MD / SDSC because, if you were forced to explain MD >>> in terms of a graph of majority-strength defeats, it would say that if A has a >>> majority over B and B doesn't have a majority over anyone, then B can't win. >>> >>> MD basically says that if there are two frontrunners and everyone truncates their >>> less liked frontrunner, then the worse frontrunner won't win. If this property >>> doesn't hold, it means the majority has done something to stop the method from >>> "seeing" their majority, which is surely that they ranked other candidates above >>> the preferred frontrunner. So MD is mostly about compromise incentive. >>> >>> SFC is probably going to be about truncation. When a method fails it, most likely >>> it's because the majority gave the election away to a less liked compromise choice. >>> For example: >>> >>> 20 C>A>B >>> 35 A>B >>> 5 B >>> 40 D >>> >>> Here B is the implicit approval winner, but by SFC B should not win, because it >>> means it was not safe for the A voters to rank B. >>> >>> I would not like to see SFC as totally obsolete, since it was one of the motivating >>> criteria (along with MD and weak FBC) for my methods MDDA and MAMPO :) >>> >>> Kevin >>> votingmethods.net <http://votingmethods.net> >>

Hi Chris, Chris Benham <cbenhamau@yahoo.com.au> a écrit : > > What I call inherently of value would be things like sincere Condorcet efficiency or > > reduced strategic incentives. >  > I can understand voted Smith-set fundamentalism, and that is expensive enough. But if > there is a top cycle I don't share the mind-set "Probably there is a sincere CW > (concealed by strategic truncation or order-reversal) and our top priority should be to > infer or guess who that is and elect him/her."  There may well be no sincere CW or a > higher SU candidate. So quite nice, but mainly just a marketing benefit. I'm not sure how to read this. If I could prove that method XYZ was the best at sincere Condorcet efficiency (or substitute SU if you prefer), you would categorize that as mainly a marketing benefit? To me this is the entire thing that the method is supposed to be doing. > https://electowiki.org/wiki/Strategy-free_criterion >  > If a Condorcet candidate exists, and if a majority prefers this candidate to another > candidate, then the other candidate should not win if that majority votes sincerely and > no other voter falsifies any preferences. >  > I think that is very similar to the Generalised Majority Criterion, It's much more limited. > enough for me to > reject it on the same grounds. And even if I didn't have that criticism, I don't see > why it's something we should care much about. It looks like something contrived just to > serve as ammunition against Hare and Margins. It does have that role, but Hare/Margins already fail the other criteria. I have always viewed SFC as an explanation of what could be improved in Approval. I would not say someone needs to care about SFC specifically, but it addresses truncation incentive, so it isn't useless to satisfy it. > (And possibly the similar GMC was contrived just to help promote the Schulze method.) If one thinks GMC was contrived just to support Schulze(WV), it's worth asking how Woodall also managed to invent it (as CDTT). > I would think that if the method > is making some attempt to minimise the number of "wasted votes", then > many voters would want to be able to express their full sincere ranking > and also would at least not mind giving their sincere or semi-sincere > approval cutoff. I have nothing against explicit cutoffs. Kevin votingmethods.net

Kevin, > If one thinks GMC was contrived just to support Schulze(WV), it's worth asking how > Woodall also managed to invent it (as CDTT). Too easy. Woodall's  CDTT was merely a set and not a normative criterion.  He never said that he thought that the winner should come from the CDTT set. > If I could prove that method XYZ was the best at > sincere Condorcet efficiency (or substitute SU if you prefer), you would categorize > that as mainly a marketing benefit? Talking about sincere Condorcet efficiency (and not SU)  among methods that meet voted Smith, yes.  The sincere (voted or not) CW's status could be based on some very weak, barely existing, pairwise preferences. If the identity of this CW has been "concealed" by voters choosing (or not bothering) to express them, then big deal. > I have nothing against explicit cutoffs. I'm glad to hear it.  Methods in that category that meet Double Defeat cut through a few Gordian knots, and render all (or nearly all) of the rankings-only "defensive strategy" criteria irrelevant. More on this later. Chris B. On 24/06/2024 7:38 am, Kevin Venzke wrote: > Hi Chris, > > Chris Benham <cbenhamau@yahoo.com.au> a écrit : >>> What I call inherently of value would be things like sincere Condorcet efficiency or >>> reduced strategic incentives. >> >> I can understand voted Smith-set fundamentalism, and that is expensive enough. But if >> there is a top cycle I don't share the mind-set "Probably there is a sincere CW >> (concealed by strategic truncation or order-reversal) and our top priority should be to >> infer or guess who that is and elect him/her."  There may well be no sincere CW or a >> higher SU candidate. So quite nice, but mainly just a marketing benefit. > I'm not sure how to read this. If I could prove that method XYZ was the best at > sincere Condorcet efficiency (or substitute SU if you prefer), you would categorize > that as mainly a marketing benefit? To me this is the entire thing that the method > is supposed to be doing. > >> https://electowiki.org/wiki/Strategy-free_criterion >> >> If a Condorcet candidate exists, and if a majority prefers this candidate to another >> candidate, then the other candidate should not win if that majority votes sincerely and >> no other voter falsifies any preferences. >> >> I think that is very similar to the Generalised Majority Criterion, > It's much more limited. > >> enough for me to >> reject it on the same grounds. And even if I didn't have that criticism, I don't see >> why it's something we should care much about. It looks like something contrived just to >> serve as ammunition against Hare and Margins. > It does have that role, but Hare/Margins already fail the other criteria. I have > always viewed SFC as an explanation of what could be improved in Approval. > > I would not say someone needs to care about SFC specifically, but it addresses > truncation incentive, so it isn't useless to satisfy it. > >> (And possibly the similar GMC was contrived just to help promote the Schulze method.) > If one thinks GMC was contrived just to support Schulze(WV), it's worth asking how > Woodall also managed to invent it (as CDTT). > >> I would think that if the method >> is making some attempt to minimise the number of "wasted votes", then >> many voters would want to be able to express their full sincere ranking >> and also would at least not mind giving their sincere or semi-sincere >> approval cutoff. > I have nothing against explicit cutoffs. > > Kevin > votingmethods.net

Richard, I believe Double defeat Hare is also known as RCIPE. https://electowiki.org/wiki/Ranked_Choice_Including_Pairwise_Elimination On Sat, Jun 22, 2024, 07:43 Richard, the VoteFair guy < electionmethods@votefair.org> wrote: > On 6/22/2024 1:31 AM, Chris Benham wrote: > > I think those of us who are extra hung-up about frustrating Burial > > should look more closely at Double Defeat, Hare. ... > > What is Double Defeat Hare? > > I didn't try to find it on Electowiki because lately that website has > not been responding when I click on links to it. > > Richard Fobes > the VoteFair guy > (and now the only Richard here) > > > On 6/22/2024 1:31 AM, Chris Benham wrote: > > Kevin, > > > > Something I didn't address in my previous email: > > > >>> And what is wrong with your "Improved > >>> Condorcet Approval" method ? I think it would be good using > >>> unrestricted ranking ballots with an explicit approval cutoff. > >> ICA or C//A (implicit) are not bad. They don't satisfy SFC. In my > >> recent simulations > >> on frontrunner truncation strategy, C//A is among the best Condorcet > >> methods. In > >> random elections I am disturbed that ICA and C//A are worse than WV > >> methods at > >> strong FBC (i.e. what I call compromise incentive). > >> > >> You've asked me many times about C//A(explicit) and I still think it's > >> bad. The > >> entire notion of C//A(implicit) being good at deterring burial is > >> based on the > >> fact that if you use burial to prevent there from being a Condorcet > >> winner, then in > >> the "cycle resolution" you cannot prefer any candidate to the one you > >> raised > >> insincerely. > >> > >> In C//A(explicit), burial only backfires if it actually creates a fake > >> CW. Creating > >> a fake cycle is never bad for your favorite. > > > > In these mass public elections the chance that an individual voter's > > ballot will be pivotal is negligible. I would think that if the method > > is making some attempt to minimise the number of "wasted votes", then > > many voters would want to be able to express their full sincere ranking > > and also would at least not mind giving their sincere or semi-sincere > > approval cutoff. For example in a Hare (aka IRV) election (with > > unrestricted strict ranking from the top) I can't imagine it ever > > crossing my mind to vote insincerely (and I never have). > > > > Also I think the method needs to have some justification on the > > assumption that the voters are sincere. So if voters complain "Why > > aren't I allowed to rank among the candidates I don't approve?" and "How > > do we know that the voted CW is really the CW if we have been forced to > > truncate our rankings?", we need some answer that isn't just about > > "deterring burial". We could say "Well this is more simple, and it's > > not strictly a Condorcet method but rather an Approval-Condorcet hybrid > > that is trying to produce a high SU winner" but I expect that a lot of > > voters would not be fully satisfied with that answer. (I wouldn't be.) > > > > I have become firmer in my support for Double Defeat (explicit) methods > > and my favourite of these is Margins-Sorted Approval. Those method allow > > voters to rank however many candidates they wish and also give a > > approval cutoff, and no candidate that is pairwise-beaten by a more > > approved candidate is allowed to win. Much of the time this is by itself > > decisive. > > > > I think those of us who are extra hung-up about frustrating Burial > > should look more closely at Double Defeat, Hare. I suspect that it has > > most of the Condorcet efficiency of an actual Condorcet method while > > retaining most of the Burial resistance of Hare, while possibly tending > > to give higher SU winners than both. > > > > Chris B. > > > > On 21/06/2024 9:32 pm, Kevin Venzke wrote: > >> Hi Chris, > >> > >>> On Mono-add-Plump as a weak version of Participation: > >>>> Yes but almost all proposals fail Participation, so we will be in a > >>>> lot of trouble > >>>> if we insist on this kind of thinking. > >>> What sort of "trouble"? I don't see how your conclusion follows from > >>> your premise. Why do "almost all proposals fail Participation"? It > >>> isn't because there is anything inherently wrong with "that kind of > >>> thinking". It is because it just happens that Participation is very > >>> expensive (in terms of other desirable criterion compliances, such as > >>> Condorcet). But in that way Mono-add-Plump is very very cheap (if not > >>> free), and some of us are currently "in trouble" due to disregarding > >>> "this kind of thinking". > >> What I'm saying is that if we pursue criteria in the vein of > >> Participation (or > >> monotonicity), we cut down the list of methods we can consider, and we > >> aren't > >> necessarily getting anything of value except that fewer people can > >> call the method > >> absurd. What I call inherently of value would be things like sincere > >> Condorcet > >> efficiency or reduced strategic incentives. > >> > >>> Suppose a mini-bus with a driver is contracted to pick up a group of > >>> people and take then on a trip to one of X, Y or Z after polling the > >>> passengers on their ranking-preferences among these alternative > >>> destinations. After the bus is nearly full it is mistakenly assumed > that > >>> there will be no more passengers and the driver applies some algorithm > >>> to the rankings of those present and announces that winning alternative > >>> is X. > >>> Then it is learned that there are two more passengers to come to fill > up > >>> the bus. They do so and the driver says to them "I've polled all the > >>> other passengers and at the moment the winning destination is X. Where > >>> would you like to go?" and they reply "X is our first preference and Y > >>> wouldn't be too bad and we are very glad we aren't gong to Z". > >>> The driver replies "You prefer Y to Z? In that case the new winning > >>> alternative is Y". Now if these two voters (and perhaps others whose > >>> first preference was X) were enlightened election-method experts, they > >>> might think "Obviously this fellow's election-method algorithm fails > >>> Participation (and presumably Later-no-Harm). Perhaps it meets > >>> Condorcet, which we know is incompatible with both Participation and > >>> Later-no-Harm. Perhaps before we showed up there was a top cycle and > our > >>> Y>Z preferences turned Y into the Condorcet winner. > >>> But we know that Condorcet is also incompatible with Later-no-Help so > us > >>> revealing our second preferences could have just as likely helped us, > so > >>> I suppose we were just unlucky." > >>> Or if they were not experts but charitably minded they might think "I > >>> suppose it is possible that this fellow made an honest mistake due to > >>> him being thick and us confusing him with too much information". > >>> Now replay this scenario except this time the new passengers just say > >>> "Great! We just really want to go to X and we don't know or care about > >>> any other destination." And then the driver says "In that case the > >>> winning alternative changes from X to Y". > >>> The response could only be that the destination-decider (supposedly > >>> purely based on the passengers' stated preferences) is insane (or > >>> malevolent, in any case illegitimate) and that Y is obviously an > >>> illegitimate winner. > >>> Did you notice a very different vibe from the first case, which was a > >>> failure of Participation and Mono-add-Top but not Mono-add-Plump? > >> The difference in vibe is quite similar to your own difference in vibe > >> when you > >> compare these situations. > >> > >> In one case, some voters are willing to say "I guess there were other > >> considerations > >> in play; we were unlucky" but in the other case they won't go there. > >> And that's > >> fine, that is their right. > >> > >>> In December 2008 on EM I argued that Schulze's Generalised Majority > >>> Criterion is a mistaken standard because the concept is vulnerable to > >>> Mono-add-Plump. > >> But given their compatibility, isn't that a strange thing to say? > >> > >>> Your new MDDA 2 method fails the example I gave: > >>> 25 A>B > >>> 26 B>C > >>> 23 C>A > >>> 04 C > >>> (78 ballots, majority threshold = 40) > >>> Implicit approval scores: C 53, B 51, A 48. No candidate is > >>> disqualified due to sub-majority approval. > >>> B>C 51-27, C>A 53-25, A>B 48-26. All candidates have a > >>> "majority" strength defeat, so it "isn't possible" to disqualify any > >>> candidate on that basis. So, according to the rules of MDDA 2, we > elect > >>> the most approved candidate, C. > >>> Now say we add 22 ballots that plump for C to give: > >>> 25 A>B > >>> 26 B>C > >>> 23 C>A > >>> 26 C > >>> (100 ballots, majority threshold = 51) > >>> Implicit approval scores: C 75, B 51, A 48. Now A has > sub-majority > >>> approval and so is disqualified. > >>> B>C 51-49, C>A 75-25, A>B 48-26. Now C and A have > >>> majority-strength defeats and B doesn't, so (according to the rules of > >>> MDDA 2), A (again) and C are disqualified leaving B as the new winner. > >>> The contention that C is the right winner when there were just 78 > >>> ballots but when we add 22 ballots that plump (bullet vote) for C the > >>> right winner is no longer C is .... completely crazy. > >> The voters' behavior had a side effect of strengthening B. All sorts > >> of monotonicity > >> failures take such an appearance. > >> > >> And again, there could be differences in severity, e.g. what percent > >> of voters think > >> a given phenomenon is absurd. But I don't find that very interesting > >> because it > >> doesn't tell us about the merits of the method. It's basically > >> marketability. > >> > >>>> Well, in an environment where the concept of "median voter" is likely > >>>> to be meaningful,... > >>> What "environment" is that? And why is that the environment the one we > >>> should primarily focus on? > >> One where voter and candidate preferences can be explained by an > >> underlying issue > >> space. In this case if you could project everyone onto a plane or > >> spectrum it would > >> be a bit easy to find the median voter and their preferred candidate. > >> > >> I think this usually describes public elections, but it probably > >> wouldn't cover a > >> vote on what color is the best, or a vote on what cuisine to have > >> delivered. So I > >> think we should probably have IIB for those cases. > >> > >>> I think that is the sort of thinking that > >>> leads some people to support Median Ratings methods, which we know are > >>> garbage because they fail Dominant Candidate and Irrelevant Ballots > >>> Independence, and the voters have a strong incentive to just submit > >>> approval ballots (giving the same result as Approval). And it has led > >>> you to the absurdity of suggesting a method that fails Mono-add-Plump. > >> Not at all, median rating methods aren't motivated by the notion of a > >> single median > >> voter. There are multiple median voters on different posed questions, > >> and that's > >> true on a pairwise matrix as well. > >> > >>> I think for the purposes of properly analysing single-winner election > >>> methods and inspiring the invention of new ones, we can and should do > >>> without criteria that refer to irrelevant ballots dependent "majority" > >>> thresholds or pairwise defeats. Those have almost no positive point > >>> aside from marketing. > >> You're saying that criteria directly specifying "majority" and not > >> something else > >> is what lacks positive points aside from marketing? That could be true. > >> > >>> My suggestion for something as close as possible to Minimal Defense: > >>> *If the number of ballots that vote X above bottom and Y no higher than > >>> equal-bottom is greater than Y's maximum pairwise support, then Y can't > >>> win.* > >> I don't hate that. I don't know what you gain from using "max pairwise > >> support" > >> instead of "votes in total." > >> > >>> I propose Double Defeat (Implicit) as something that can substitute for > >>> the votes-only versions of Minimal Defense and SFC and also Plurality. > >>> *Interpreting ranking (or ranking above equal bottom) as approval, no > >>> candidate that is pairwise-beaten by a more approved candidate is > >>> allowed to win.* > >> It's interesting but it doesn't cover SFC. In an SFC failure scenario > the > >> disqualified candidate might very well have more approval than the > >> candidate who > >> disqualifies them. The concern is that supporters of the latter gave > >> the election > >> away. > >> > >>> That already inspires a simple method suggestion: DDI,MMM: *Elect the > >>> candidate not disqualified by Double-Defeat (Implicit) that is highest > >>> ordered by MinMax(Margins).* > >>> What do you think of that? > >> I don't like it but it might be fine. > >> > >>> And what is wrong with your "Improved > >>> Condorcet Approval" method ? I think it would be good using > >>> unrestricted ranking ballots with an explicit approval cutoff. > >> ICA or C//A (implicit) are not bad. They don't satisfy SFC. In my > >> recent simulations > >> on frontrunner truncation strategy, C//A is among the best Condorcet > >> methods. In > >> random elections I am disturbed that ICA and C//A are worse than WV > >> methods at > >> strong FBC (i.e. what I call compromise incentive). > >> > >> You've asked me many times about C//A(explicit) and I still think it's > >> bad. The > >> entire notion of C//A(implicit) being good at deterring burial is > >> based on the > >> fact that if you use burial to prevent there from being a Condorcet > >> winner, then in > >> the "cycle resolution" you cannot prefer any candidate to the one you > >> raised > >> insincerely. > >> > >> In C//A(explicit), burial only backfires if it actually creates a fake > >> CW. Creating > >> a fake cycle is never bad for your favorite. > >> > >> Kevin > >> votingmethods.net > >> > > ---- > > Election-Methods mailing list - see https://electorama.com/em for list > info > ---- > Election-Methods mailing list - see https://electorama.com/em for list > info >

Double Defeat,Hare means you form a candidate ranking using the IRV elimination order and then you elect the first (i.e. best, last-eliminated) candidate in the ranking who is permissible under Chris Benham's Double Defeat criterion. The criterion says you can't be elected if you have less approval than a candidate who pairwise defeats you. The comma is key to deciphering the name. Kevin votingmethods.net Le dimanche 23 juin 2024 à 22:03:06 UTC−5, Ted Stern <dodecatheon@gmail.com> a écrit : Richard, I believe Double defeat Hare is also known as RCIPE. https://electowiki.org/wiki/Ranked_Choice_Including_Pairwise_Elimination On Sat, Jun 22, 2024, 07:43 Richard, the VoteFair guy <electionmethods@votefair.org> wrote: > On 6/22/2024 1:31 AM, Chris Benham wrote: >  > I think those of us who are extra hung-up about frustrating Burial >  > should look more closely at Double Defeat, Hare.  ... > > What is Double Defeat Hare? > > I didn't try to find it on Electowiki because lately that website has > not been responding when I click on links to it. > > Richard Fobes > the VoteFair guy > (and now the only Richard here) >

On 6/23/2024 8:34 PM, Kevin Venzke wrote: > Double Defeat,Hare means you form a candidate ranking using the IRV elimination order and then you elect the first (i.e. best, last-eliminated) candidate in the ranking who is permissible under Chris Benham's Double Defeat criterion. The criterion says you can't be elected if you have less approval than a candidate who pairwise defeats you. So the "Double Defeat,Hare" method requires that each voter indicate an approval cutoff within their ranked choice ballot? So we cannot use the Double Defeat,Hare method on the Burlington election data, right? How would the Approval cutoff be indicated on a ranked choice ballot on which the voter marks ovals in "choice" columns? I'm asking because that's the only kind of ballot used here in Oregon, where everyone votes at home. Since Ted mentioned the RCIPE method (ranked choice including pairwise elimination), I'll mention the RCIPE method does not require an approval cutoff, and the RCIPE method would have elected the Condorcet winner in the Burlington election. Richard Fobes (now the only Richard on the E-M list) (FYI, I include "the VoteFair guy" as part of my email address to help someone scan the large number of election-method emails she gets in her inbox.) > > The comma is key to deciphering the name. > > Kevin > votingmethods.net > > > > Le dimanche 23 juin 2024 à 22:03:06 UTC−5, Ted Stern <dodecatheon@gmail.com> a écrit : > > Richard, I believe Double defeat Hare is also known as RCIPE. > > https://electowiki.org/wiki/Ranked_Choice_Including_Pairwise_Elimination > > On Sat, Jun 22, 2024, 07:43 Richard, the VoteFair guy <electionmethods@votefair.org> wrote: >> On 6/22/2024 1:31 AM, Chris Benham wrote: >>  > I think those of us who are extra hung-up about frustrating Burial >>  > should look more closely at Double Defeat, Hare.  ... >> >> What is Double Defeat Hare? >> >> I didn't try to find it on Electowiki because lately that website has >> not been responding when I click on links to it. >> >> Richard Fobes >> the VoteFair guy >> (and now the only Richard here) >>