I agree with Chris. But mostly, I'm writing to say that I would really like someone to fill in:
http://wiki.electorama.com/wiki/MDDTR http://wiki.electorama.com/wiki/MTA Of course, redirects are fine. And you don't have to put in all sorts of sections for compliances and such if you don't know them, just a few sentences explaining the method itself is plenty. Thanks, Jameson 2011/11/17 C.Benham <[email protected]> > > 49: C >> 27: A>B >> 24: B >> >> I agree that *if* the sincere preferences are as Mike specifies then a >> just interventionist mind-reading God >> should award the election to A. >> >> [endquote] >> >> Fine. But can Chris say what's wrong with that outcome in other instances? >> > > > Yes. If the method used meets Later-no-Harm but fails Later-no-Help, i.e > has > a strong random-fill incentive like the MDD,TR method that Mike is > advocating, there > isn't any good reason to assume that the Middle ratings are sincere. > > So it could be that all the voters really have no interest in any > candidate except their favourites > and sincere is > > 49: C > 27: A > 24: B > > in which case C is the strong sincere Condorcet winner, or as Jameson > pointed out it could > be worse still and the A voters were Burying against C so sincere is > > 49: C > 27: A>C > 24: B > > > Chris continues: >> >> Given the incentives of the MDD,TR method that Mike is advocating, it is >> only reasonable to assume that the truncators >> are all sincere >> >> [endquote] >> >> Wait a minute: I'm not saying that B truncation is a problem in MDDTR or >> MMPO. In fact, >> my point is that it is _not_. >> > > > Truncation isn't a "problem" (for the full-rankers) as an "offensive > strategy". The problem is that it > isn't fair to the sincere truncators. > > > Wait a minute. These candidates in this example are A, B, and C. >> >> How does A lack legitimacy? Among the candidates not majority-defeated, A >> has more favoriteness-supporters than any other candidate. >> > > > Translation: "I love this arbitrary algorithm, so any winner it produces > is by definition legitimate." > > A's win lacks legitimacy simply because there is another candidate that > was vastly better supported on > the ballots. > > If we add between 2 and 21 ballots that plump for A, then C's > "majority-defeatedness" goes away and > the winner changes from A to C, another failure of Mono-add-Plump. > > If we nonetheless accept that C but not A should be immediately > disqualified, electing the undisqualified > candidate with the most top-ratings is just another arbitrary feature of > the algorithm. > > Why that candidate and not the one that is most approved? Based on the > information actually on the ballots, > no faction of voters has a very strong post-election complaint against B. > > Chris Benham > > > 49: C > 27: A>B > 21: A (new voters, whose ballots change the MDD,TR winner from A to C) > 24: B > > > > > Mike Ossipoff wrote (17 Nov 2011): > > Chris said: > > Mike refers to this scenario: > > > The Approval bad-example is an example of that. I'll give it again here: > > > > Sincere preferences: > > > > 49: C > > 27: A>B > > 24: B>A > > > > A majority _equally strongly_ prefer A and B to C. > > > > > > Actual votes: > > > > The A voters defect, in order to take advantage of the > > co-operativeness and > > responsibility of the A voters: > > > > 49: C > > 27: A>B > > 24: B > > > > I agree that *if* the sincere preferences are as Mike specifies then a > just interventionist mind-reading God > should award the election to A. > > [endquote] > > Fine. But can Chris say what's wrong with that outcome in other instances? > > Chris continued: > > But a voting method's decisions and philosophical justification should > be based on information that is actually > on the ballots, not on some guess or arbitrary assumption about some > maybe-existing "information" that isn't. > > [endquote] > > Why? Why shouldn't a voting system avoid a worst-case, if, by so doing, > it hasn't been shown to act seriously wrongly in other cases? > > And MMPO & MDDTR don't just bring improvement in the Approval bad-example. > They, > in general, get rid of any strategy dilemma regarding whether you should > middle-rate > a lesser-evil instead of bottom-rating hir. For instance, consider the > A 100, B 15, C 0 utility example. > > In MCA, there's a question about whether you should middle-rate or > bottom-rate B. In > MDDTR and MMPO, that dilemma is completely eliminated. > > In those methods, middle rating someone can never help hir against your > favorite(s). > > Chris continues: > > I think a very reasonable tenet is that if, based on the information on > the ballots, candidate X utterly dominates > candidate Y then we should not elect Y. > > [endquote] > > Yes, there are many reasonable tenets among the aesthetic criteria. > > Chris continues: > > For several reasons (for those who can pooh-pooh this as "merely > aesthetic"): electing Y gives the supporters > of X a very strong post-election complaint with no common-sense or > philosophically cogent answer, X is highly > likely to be higher Social Utility (SU), Y's victory will have > compromised legitimacy. > > [endquote] > > Wait a minute. These candidates in this example are A, B, and C. > > How does A lack legitimacy? Among the candidates not majority-defeated, A > has more favoriteness-supporters than any other candidate. > > Chris continues: > > The Plurality criterion is one very reasonable criterion that says that > C is so much stronger than A that the election > of A can't be justified. . > > [endquote] > > There are lots of aesthetic criteria that say things like that, and they > all sound > aesthetically reasonable. How great is their practical strategic > importance? > > > Chris continued: > > There are other criteria I find reasonable > that say the same thing: > > "Strong Minimal Defense": If the number of ballots on which both X is > voted above bottom and Y isn't is greater than > the total number of ballots on which Y is voted above bottom, then don't > elect Y. > > [endquote] > > But can you word that in such a way that it isn't met by Plurality? > > What sort of strategic guarantees are protected by the criteria > that you propose in this posting? > > Chis continues: > > The election of A is unacceptable because C's domination of A is > vastly more impressive than A's pairwise win over > B. The Plurality criterion plus the three other criteria I define above > all loudly say "not A". > > [endquote] > > In other words, it looks bad from those perspectives. > > The election of A is justified by its being consistent with FBC, SFC or > SFC3, > freedom from dilemma about middle-rating a compromise, and either > Later-No-Harm or non"failure" in Kevin's MMPO bad-example. --things that > are > guaranteed by MMPO and MDDTR. > > Additionally, as I was showing to Jameson, electing A in these methods > isn't really wrong. > > > > > The A voters defect, in order to take advantage of the > > co-operativeness and > > responsibility of the A voters: > > Chris replies: > > The plausibility of arbitrary claims about the voters' sincere > preferences and motivations > > [endquote] > > More a matter of "what if", rather than claims. > > Chris continued: > > can weighed in the light of the > used election method's incentives. How is it so "co-operative and > responsible" of the A voters to rank B when doing > so (versus truncating) can only help their favourite? > > [endquote] > > It's co-operative because it defeats the candidate commonly disliked by A > voters and B voters, in MCA, MDDTR and MMPO. > > If neither did that, C would win. > > If the A voters refused to, and, instead, the B voters co-operated, then > it would > be B would win, by being the defectors. > > Chris continues: > > And why would the > B voters be insincerely truncating ("defecting") > when doing so can only harm their favourite? > > [endquote] > > In MCA that defection could give their favorite the win, if the A voters > have > co-operated, in spite of the A voters being more numerous. > > In MPPO or MDDTR, the problem doesn't exist. The A voters can co-operate or > defect, and A will still win, having more top ratings. Hardly a > controversial > result. > > Chris continues: > > Given the incentives of the MDD,TR method that Mike is advocating, it is > only reasonable to assume that the truncators > are all sincere > > [endquote] > > Wait a minute: I'm not saying that B truncation is a problem in MDDTR or > MMPO. In fact, > my point is that it is _not_. But co-operaton/defection is indeed a > problem in MCA. > Hency my advocacy of MDDTR and MMPO. > > > ---- > Election-Methods mailing list - see http://electorama.com/em for list info >
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