[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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