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<pre><br>Chris said:<br><br>Mike refers to this scenario:<br> <br>> The Approval bad-example is an example of that. I'll give it again here:<br>><br>> Sincere preferences:<br>><br>> 49: C<br>> 27: A>B<br>> 24: B>A<br>><br>> A majority _equally strongly_ prefer A and B to C.<br>><br>><br>> Actual votes:<br>><br>> The A voters defect, in order to take advantage of the <br>> co-operativeness and<br>> responsibility of the A voters:<br>><br>> 49: C<br>> 27: A>B<br>> 24: B<br>><br> <br>I agree that *if* the sincere preferences are as Mike specifies then a <br>just interventionist mind-reading God<br>should award the election to A.<br><br>[endquote]<br><br>Fine. But can Chris say what's wrong with that outcome in other instances?<br><br>Chris continued:<br> <br>But a voting method's decisions and philosophical justification should <br>be based on information that is actually<br>on the ballots, not on some guess or arbitrary assumption about some <br>maybe-existing "information" that isn't.<br><br>[endquote]<br><br>Why? Why shouldn't a voting system avoid a worst-case, if, by so doing,<br>it hasn't been shown to act seriously wrongly in other cases?<br> <br>And MMPO & MDDTR don't just bring improvement in the Approval bad-example. They,<br>in general, get rid of any strategy dilemma regarding whether you should middle-rate<br>a lesser-evil instead of bottom-rating hir. For instance, consider the <br>A 100, B 15, C 0 utility example.<br><br>In MCA, there's a question about whether you should middle-rate or bottom-rate B. In<br>MDDTR and MMPO, that dilemma is completely eliminated.<br><br>In those methods, middle rating someone can never help hir against your favorite(s).<br><br>Chris continues:<br><br>I think a very reasonable tenet is that if, based on the information on <br>the ballots, candidate X utterly dominates<br>candidate Y then we should not elect Y.<br><br>[endquote]<br><br>Yes, there are many reasonable tenets among the aesthetic criteria.<br><br> Chris continues:<br><br>For several reasons (for those who can pooh-pooh this as "merely <br>aesthetic"): electing Y gives the supporters<br>of X a very strong post-election complaint with no common-sense or <br>philosophically cogent answer, X is highly<br>likely to be higher Social Utility (SU), Y's victory will have <br>compromised legitimacy.<br><br>[endquote]<br><br>Wait a minute. These candidates in this example are A, B, and C.<br><br>How does A lack legitimacy? Among the candidates not majority-defeated, A<br>has more favoriteness-supporters than any other candidate.<br><br> Chris continues:<br><br>The Plurality criterion is one very reasonable criterion that says that <br>C is so much stronger than A that the election<br>of A can't be justified. .<br><br>[endquote]<br><br>There are lots of aesthetic criteria that say things like that, and they all sound<br>aesthetically reasonable. How great is their practical strategic importance?<br><br><br>Chris continued:<br><br>There are other criteria I find reasonable <br>that say the same thing:<br> <br>"Strong Minimal Defense": If the number of ballots on which both X is <br>voted above bottom and Y isn't is greater than<br>the total number of ballots on which Y is voted above bottom, then don't <br>elect Y.<br><br>[endquote]<br><br>But can you word that in such a way that it isn't met by Plurality?<br><br>What sort of strategic guarantees are protected by the criteria<br>that you propose in this posting?<br><br>Chis continues:<br><br>The election of A is unacceptable because C's domination of A is <br>vastly more impressive than A's pairwise win over<br>B. The Plurality criterion plus the three other criteria I define above <br>all loudly say "not A".<br><br>[endquote]<br><br>In other words, it looks bad from those perspectives.<br><br>The election of A is justified by its being consistent with FBC, SFC or SFC3,<br>freedom from dilemma about middle-rating a compromise, and either <br>Later-No-Harm or non"failure" in Kevin's MMPO bad-example. --things that are<br>guaranteed by MMPO and MDDTR.<br><br>Additionally, as I was showing to Jameson, electing A in these methods<br>isn't really wrong.<br> <br><br> <br>> The A voters defect, in order to take advantage of the <br>> co-operativeness and<br>> responsibility of the A voters:<br> <br> Chris replies:<br><br>The plausibility of arbitrary claims about the voters' sincere <br>preferences and motivations<br><br>[endquote]<br><br>More a matter of "what if", rather than claims.<br><br>Chris continued:<br><br>can weighed in the light of the<br>used election method's incentives. How is it so "co-operative and <br>responsible" of the A voters to rank B when doing<br>so (versus truncating) can only help their favourite?<br><br>[endquote]<br><br>It's co-operative because it defeats the candidate commonly disliked by A<br>voters and B voters, in MCA, MDDTR and MMPO.<br><br>If neither did that, C would win.<br><br>If the A voters refused to, and, instead, the B voters co-operated, then it would<br>be B would win, by being the defectors.<br><br>Chris continues:<br><br>And why would the <br>B voters be insincerely truncating ("defecting")<br>when doing so can only harm their favourite?<br><br>[endquote]<br><br>In MCA that defection could give their favorite the win, if the A voters have<br>co-operated, in spite of the A voters being more numerous.<br><br>In MPPO or MDDTR, the problem doesn't exist. The A voters can co-operate or<br>defect, and A will still win, having more top ratings. Hardly a controversial<br>result.<br><br>Chris continues:<br><br>Given the incentives of the MDD,TR method that Mike is advocating, it is <br>only reasonable to assume that the truncators<br>are all sincere<br><br>[endquote]<br><br>Wait a minute: I'm not saying that B truncation is a problem in MDDTR or MMPO. In fact,<br>my point is that it is _not_. But co-operaton/defection is indeed a problem in MCA.<br>Hency my advocacy of MDDTR and MMPO.<br><br> </pre> </div></body>
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