[EM] Electorama/wiki
Stéphane Rouillon
stephane.rouillon at sympatico.ca
Fri Nov 18 19:08:13 PST 2011
How do we save Edits on the electowiki....?
I can't see changes I made to the Proportional Representation page..
On 2011-11-18 00:18, Jameson Quinn wrote:
> 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 <cbenhamau at yahoo.com.au
> <mailto:cbenhamau at yahoo.com.au>>
>
>
> 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.
>
>
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>
>
>
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