[EM] "Double Defeat, Hare" poll candidate

[Michael Garman]

Is the poll still happening? I thought Ossipoff cancelled it when he rage
quit the forum.
On Tue, Apr 16, 2024 at 4:50 PM Chris Benham <cbenhamau at yahoo.com.au> wrote:

>
> I would like to nominate  Double Defeat, Hare.
>
> *Voters strictly rank from the top however many candidates they wish and
> also may specify an approval cutoff.
>
> Default approval is only goes to top-ranked candidates.
>
> All candidates that are pairwise beaten by a more approved candidate are
> disqualified.
>
> If that leaves more than one qualified (i.e. not disqualified)
> candidate, commence eliminations according to Hare
> rules until only one qualified candidate remains.*
>
> This is a compromise between Hare and Condorcet which will probably not
> please the fundamentalist supporters of either,
> because it doesn't meet the Condorcet criterion and is more complicated
> than Hare and fails Later-no-Harm and Later-no-Help.
>
> But it addresses the concern some have about electing a weak low social
> utility Condorcet winner, and I think it might simulate
> well.
>
>
> I think that methods that allow voters to both rank the candidates and
> specify an approval threshold/cutoff
> should never elect a candidate that is pairwise beaten by a more approved
> candidate.
>
> I coined this criterion as "Double Defeat" and it occurred to me that it
> could be a disqualification device that
> is part of a method.
>
> Some people are wary of Condorcet electing a "weak centrist" candidate,
> for example
>
> 49 A>>>C>B
> 48 B>>>C>A
> 03 C>A>>>B
>
> Assuming all voters get the same utility from electing their favourites,
> the Hare (and FPP and presumably Approval)
> winner is the highest Social Utility candidate A.
>
> With those sincere preferences, the ranking-with-specified-approval
> ballots would be
>
> 49 A|>C
> 48 B|>C
> 03 C>A|
>
> Here the Double Defeat rule doesn't interfere with Hare.  B is
> disqualified because B is pairwise beaten by the more approved A.
>
> So then, following Hare rules C is eliminated leaving A as the only
> qualified candidate and so winner.
>
> The C>A voters have no real complaint other than "The method should meet
> the Condorcet criterion" and any complaint from
> the B>C voters is answered by "To get a result you prefer you didn't have
> to order-reverse, you could have had A disqualified by
> approving C".
>
> The method is similar in spirit to an "Approval-enhanced Hare" that arose
> from discussion I had here a few months ago with Forest,
> but which I forgot about and didn't rediscover until after nominations for
> the poll had closed:
>
> *Elect the most approved member of the set comprising the Hare winner and
> all the candidates with a beat-path to the Hare winner.*
>
> 49 A (sincere might be A>B)
> 24 B (sincere might be B>C)
> 27 C>B
>
> A classic example that has been interpreted as Hare and Margins by
> electing A failing Minimal Defense and avoidably causing the C voters to
> regret
> not Compromising, and alternatively by electing B the C>B voters having
> been taken advantage of by the B voters using a Defection strategy, a
> failure
> of the Chicken Dilemma criterion.
>
> In this example it is true that in all the methods that meet Double Defeat
> it is up to the C>B voters to decide which is more important for them:
> preventing the election of their greater evil A, or preventing being taken
> advantage of by Defecting B voters.
>
> Chris B.
>
>
>
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>
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