[EM] Relative vs. Majority Condorcet
Chris Benham
cbenhamau at yahoo.com.au
Sun Apr 28 12:34:51 PDT 2024
CLC,
>
> Yes, that's the main question I'm looking to answer with this poll: do
> tied-at-the-top, or other tied-rank mechanisms, have substantial
> support on this email list? (ICT is a similar, but not-quite-working,
> attempt at satisfying Minimal Defense as well.)
I assume by "mechanisms" you mean * mechanisms to force the method to
comply with Favorite Betrayal*. As far as I can tell, no.
The way you describe ICT I find a bit odd. Kevin's ICA method easily
meets Minimal Defense. ICT instead meets Chicken Dilemma (incompatible
with Minimal Defense) but I think I recall was motivated by some example
where the MCA winner looked quite odd.
I don't recall it but can probably find it later.
Chris B.
On 28/04/2024 12:40 pm, Closed Limelike Curves wrote:
> Hi Chris, thanks for your response!
>
> I came to the conclusion that any good more sophisticated FBC
> methods need to use Kevin's "Tied at the Top Rule" mechanism.
>
> Yes, that's the main question I'm looking to answer with this poll: do
> tied-at-the-top, or other tied-rank mechanisms, have substantial
> support on this email list? (ICT is a similar, but not-quite-working,
> attempt at satisfying Minimal Defense as well.)
>
> There is some small movement and enthusiasm for Condorcet
> compliance, but none that I discern for strict FBC compliance. I
> would think most voters would satisfied with the massive reduction
> in Compromise incentive compared to FPP afforded by properly
> implemented IRV, let alone the still greater reduction we get from
> Condorcet.
>
> There's a major IRV-repeal effort underway in Alaska at the moment
> because they had one (!) election with a favorite-betrayal incentive.
> I'm also not aware of any movements for strict relative-majority
> Condorcet compliance. The organization that comes closest is EVC (with
> their Copeland//Borda proposal), but even they're not very purist
> about it.
>
> And I'm generally allergic to, and find very silly, methods that
> fail Irrelevant Ballots Independence like Median Ratings methods
> and this "Majority-Condorcet" idea.
>
> I fully agree with you that this is a big problem for median ratings.
> A voter who shows up and says they think all the candidates are bad
> isn't provide any new information about the relative quality of the
> candidates.
> However, I don't think an all-equal ballot is providing no
> information in every situation. As an example, say we had a system
> like approval, but with a 50% threshold for election (and elections
> with <50% support for the winner resulting in reopening nominations).
> Then, a fully-blank ballot is a way for voters to meaningfully express
> their preference for somebody else,//other than the current crop of
> candidates.
>
> Something similar applies to the tied-at-the-top rule: a voter who
> ties two candidates is saying they want these two candidates to be
> compared using the tiebreaking mechanism, /rather than/ the
> relative-Condorcet mechanism.
>
> On Sat, Apr 27, 2024 at 5:00 AM Chris Benham <cbenhamau at yahoo.com.au>
> wrote:
>
>> There was some advantage of ICA & ICT that I really liked, but
>> public proposals have to be as simple as possible.
>
> In that case I say forget about FBC methods other than Approval.
> I came to the conclusion that any good more sophisticated FBC
> methods need to use Kevin's "Tied at the Top Rule" mechanism.
>
> There is some small movement and enthusiasm for Condorcet
> compliance, but none that I discern for strict FBC compliance. I
> would think most voters would satisfied with the massive reduction
> in Compromise incentive compared to FPP afforded by properly
> implemented IRV, let alone the still greater reduction we get from
> Condorcet.
>
> In general FBC is much more slippery and "expensive" (in terms of
> being compatible with other criteria) than Condorcet. I went off
> my own "Irrelevant-Ballot Independent Fall-back Approval" idea
> (which isn't "very simple") when Kevin showed that it fails
> Woodall's Plurality criterion.
>
> And I'm generally allergic to, and find very silly, methods that
> fail Irrelevant Ballots Independence like Median Ratings methods
> and this "Majority-Condorcet" idea.
>
> You have an apparent "majority Condorcet" winner, and then a few
> extra ballots that vote for nobody are found and then the winner
> changes because the "majority" threshold goes up. Absurd and
> potentially embarrassing.
>
> Chris B.
>
> On 27/04/2024 3:40 pm, Michael Ossipoff wrote:
>> There was some advantage of ICA & ICT that I really liked, but
>> public proposals have to be as simple as possible. Few methods
>> proposed here are simple enough for public proposal.
>>
>> On Fri, Apr 26, 2024 at 22:50 Michael Ossipoff
>> <email9648742 at gmail.com> wrote:
>>
>>
>>
>> On Wed, Apr 24, 2024 at 10:02 Closed Limelike Curves
>> <closed.limelike.curves at gmail.com> wrote:
>>
>> /Does "Majority-Condorcet" mean the CW needs to have a
>> majority over every other
>> candidate?/
>>
>> Yes: a CW needs more than 50% of the vote, including tied
>> ranks, to defeat every other candidate. This version of
>> Condorcet is compatible with FBC.
>>
>>
>> I guess a lot of CWs wouldn’t be getting elected.
>>
>> The best Condorcet methods don’t importantly fail FBC. A
>> sincere CW can only lose by offensive strategy, & the better
>> Condorcet methods well-deter offensive strategy. No need for
>> any defensive strategy.
>>
>> Was it you who once said that people would try offensive
>> strategy? The whole point of strategy is action based on an
>> analysis of what the result will be. It’s a strategist’s
>> business to find that out first.
>>
>> Anyway when it’s noticed to usually backfire…
>>
>>
>> On Wed, Apr 24, 2024 at 3:43 AM Kristofer Munsterhjelm
>> <km_elmet at t-online.de> wrote:
>>
>> On 2024-04-24 12:32, Kevin Venzke wrote:
>>
>> > The second option doesn't offer Smith, but if it
>> did, I would note that Smith is a
>> > poor guarantee of quality. Here's a 1025-voter
>> election where a 2-vote candidate is
>> > in the Smith set (along with all other candidates):
>> >
>> > 2: A>B>C>D>E>F>G>H>I>J>K
>> > 1: B>C>D>E>F>G>H>I>J>K
>> > 2: C>D>E>F>G>H>I>J>K
>> > 4: D>E>F>G>H>I>J>K
>> > 8: E>F>G>H>I>J>K
>> > 16: F>G>H>I>J>K
>> > 32: G>H>I>J>K
>> > 64: H>I>J>K
>> > 128: I>J>K
>> > 256: J>K
>> > 512: K
>> >
>> > While this is not realistic, I do think it is
>> realistic that a candidate of limited
>> > interest to most voters would sometimes manage to
>> pairwise defeat a more viable
>> > candidate. And we should be ready to interpret this
>> as noise.
>>
>> That was phrased a bit oddly in the context of the
>> rest of your post,
>> but I understand you to be saying "the worst method
>> that passes Smith
>> may still be pretty bad", not necessarily that
>> proposed methods passing
>> Smith are actually bad. Is that right?
>>
>> -km
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