[Election-Methods] RE : Re: Is the Condorcet winner always the best?

[Stéphane Rouillon]

Satisfaction analysis should help answer your question....

Diego Santos a écrit :
> I was not enough clear when i wrote my previous email. The '>>' is not 
> a real approval mark on the ballot, it was only a "satisfaction limit" 
> from each voter. I am arguing that not always the Condorcet winner is 
> the one that maximizes happiness of the people, as Jonathan pointed.
>
> A "approval quorum" rule will avoid low utility CW to win. And, 
> opposit to Jonanthan argument, an approval cuttoff does not add too 
> much complexity: it is like a hypothetical candidate NOTB (none of the 
> below).
>
> 2007/12/11, Dave Ketchum <davek at clarityconnect.com 
> <mailto:davek at clarityconnect.com>>:
>
>     On Tue, 11 Dec 2007 12:20:49 -0800 Jonathan Lundell wrote:
>     > On Dec 11, 2007, at 6:05 AM, Kevin Venzke wrote:
>     >
>     >
>     >>Jonathan,
>     >>
>     >>--- Jonathan Lundell < jlundell at pobox.com
>     <mailto:jlundell at pobox.com>> a écrit :
>     >>
>     >>>...should choose B as a good compromise, with the A voters saying A
>     >>>is
>     >>>good, B OK, C very bad. But Diego's profile suggests to me that
>     the A
>     >>>voters are saying something like A is good, B is bad, C is very
>     bad.
>     >>>Not that they can express it in a normal linear ballot, just that
>     >>>we're being told a little more about their opinions.
>     >>
>     >>In my opinion, to the extent that the effect of a ">>bad>verybad"
>     >>vote is
>     >>disregarded, the point of letting voters indicate such
>     preferences is
>     >>undermined anyway.
>     >
>     >
>     > I'm not advocating it as a ballot option, only as a meta-notation
>     > shorthand to give us kibitzers a little more information about the
>     > voters' utility functions.
>     >
>     >
>     >>
>     >>>In my example, the effect of a later-no-harm voting rule is
>     evident.
>     >>>In Diego's, a rule (such as STV) that elects A doesn't seem
>     >>>unreasonable to me.
>     >>>
>     >>>The problem is that with an ordinary linear ballot (no '>>'), we
>     >>>can't
>     >>>distinguish between the cases. Not that I'm arguing that we should
>     >>>employ '>>'; offhand, that strikes me as a complication to be
>     >>>avoided.
>     >>
>     >>In one sense I don't agree. If >> is allowed then apparently it's
>     >>safe to
>     >>vote ">>bad>verybad." If >> isn't allowed then voters will probably
>     >>be more
>     >>cautious, since the method could very well take them as serious if
>     >>they say
>     >>that bad is better than verybad.
>     >>
>     >>I tend to think that if B doesn't win in Diego's scenario, the
>     >>method is
>     >>second-guessing the voters. It either disbelieves the C voters'
>     >>preference
>     >>for B over A, or finds that there's something more important than
>     >>majority
>     >>rule.
>     >
>     >
>     > There's a reasonable argument to be made (hardly originally by
>     me) on
>     > either side of the question of whether a compromise candidate is
>     > sometimes (or always) better to the candidate of one faction in a
>     > close election.
>     >
>     > If the vote were:
>     >
>     > 53 A
>     > 47 C
>     >
>     > ...we'd shrug and call it a fairly close election, or at least no
>     > landslide, and forget about it, even if all 100 voters strongly
>     > disapproved of the opposing candidate. If we introduce a third
>     > candidate whom the A and C voters despise only slightly less than C
>     > and A respectively, and end up with something like Diego's
>     profile, we
>     > have 100 (or 90 in that profile) unhappy voters instead of 47.
>
>     A and C agree that B is better than their standard enemy.
>
>     C voters will be happy to help install B, since this is better than
>     installing A.  A voters may be a bit unhappy, but they at least
>     avoided
>     installing C.
>
>
> Probably A supporters will be too unhappy, because their favorite 
> candidate would win if B was not nominated.
>
>     >
>     > I'm not saying that it's unarguable, nor that the voting system
>     should
>     > somehow anticipate the situation (through the use of '>>', for
>     > example). I think it's a fuzzy case with no perfect answer, and
>     that
>     > we don't really want to make the ballot more complex, or add to the
>     > possibilities for manipulation that such a rule would entail.
>     I'm just
>     > saying that it's not obvious that, in all cases, the best rule
>     is the
>     > one that lets B win.
>
>     Choices can be hard.  Get far enough from a tie and A or C will
>     win.  If
>     we manage a cycle we can debate the results of that.
>     --
>       davek at clarityconnect.com
>     <mailto:davek at clarityconnect.com>    people.clarityconnect.com/webpages3/davek
>     <http://people.clarityconnect.com/webpages3/davek>
>       Dave Ketchum   108 Halstead Ave, Owego, NY  13827-1708  
>     607-687-5026
>                 Do to no one what you would not want done to you.
>                       If you want peace, work for justice.
>
>
>
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>
>
>
>
> -- 
> ________________________________
> Diego Santos
> ------------------------------------------------------------------------
>
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