[EM] TTPBA,TR

[Jameson Quinn]

2012/1/14 MIKE OSSIPOFF <nkklrp at hotmail.com>

>  ied-at-Top-Pairwise-Beats-All, Top Ratings.
>
> In keeping with Kevin's naming, and reflecting its relation to ICA, it
> could be called
> Improved Condorcet-Top (ICT).
>
> I'll use that because it's shorter.
>
> One thing that I like about the tied-at-top methods is that they elect A
> in the ABE,
> meaning that one-sided coalition support is sufficient to defeat C, but
> without giving
> the election away to B.
>
> Of course the election of A violates the Plurality Criterion, but that's
> fine with me.
> To me, the _practical_ advantage described in the previous paragraph is
> worth more than
> the non-practical, aesthetic, Plurality Criterion.
>

In practical terms, what if the A voters rating of B is purely strategic?
I'd call such LNH-violating strategies "parasitic", and to me they're every
bit as bad as burial strategies, because they have a similar potential, if
miscalculated, to elect an entirely-undeserving candidate.

Jameson


>
> ICT has burial strategy. In the ABE, the B voters can make B win by
> burying A, by middle-
> rating C but not A. Then A doesn't have any indifference on his side, in
> hir comparison
> with C.
>
> But B still beats C, because B>C is still greater than C>B. For the same
> reason, C
> still doesn't  beat everyone.
>
> And B still beats A, because
> B>A + B=A  is greater than A>B.
>
> So B is now the only beats-all candidate. B wins.
>
> As currently defined, ICT elects C in Kevin's MMPO bad-example.
>
> No one is indifferent between A and B.
>
> So, since A=B is zero, then A>B + A=B is no greater than B>A.
>
> Likewise vice-versa, of course, since A & B are symmetrically-related.
>
> Therefore, neither beats the other.
>
> Maybe that can be fixed, by defining "beat" in the opposite way, so that x
> beats y
> if x>y is greater than y>x + x=y, and then saying that the winning set is
> the set
> of unbeaten candidates.
>
> In summary, ICT does three things that some find unacceptable:
>
> 1. Plurality Criterion violation
> 2. Successful burial strategy
> 3. Noncompliance in Kevin's MMPO bad-example.
>
> #1 and #2 aren't a problem to me. #2 could be, but I don't know what
> burial-deterrence
> ICT has.
>
> With the sole exception of MMT, the conditional methods meet
> Mono-Add-Plump.
>
> They probably meet the Plurality Criterion too, because of their close
> relation to
> Approval. If B defects, those methods elect C, in compliance with the
> Plurality Criterion.
>
> Burial strategy has no meaning in the conditional methods. As I've been
> saying, they're
> a completely new kind of method, with a new kind of strategy, a milder
> strategy.
>
> Mike Ossipoff
>
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>
>
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