[EM] minmax is not a good public election method

James Green-Armytage jarmyta at antioch-college.edu
Tue May 31 06:24:14 PDT 2005

James replying to Mike...
>This isn't in reply to any subjct-line. 

	Obviously untrue.
	Funnily enough, your statement above provides evidence against itself.
(It clearly indicates that you read my "minmax is not a good public
election method" post, and that you were concerned with it in the writing
of your message, which addresses the same salient points.)
>MMPO can fail ICC, by means of a fratricidal majority cycle. But
>in a clone-set are presumably rather similar. So how come, in that ICC 
>failure scenario,  they can muster more votes against eachother than 
>againsts their genuine opponent?
>Likewise with MMC. That majority prefer eachother's candidates to all the 
>others. And yet they contribute to greater vote totals against eachother 
>than against someone they all like less?

	Unless you mean to imply that the majority faction should use equal
rankings, your question makes no sense. That's a basic vulnerability of
ordinal-only methods: a preference between two candidates you like is
given the same weight as a preference between a candidate you like and a
candidate you strongly dislike. 
	A cycle in MMPO that thwarts a mutual majority can happen as a result of
bad luck and/or well-coordinated strategy on the part of the minority
>Condorcet Loser? It must be a peculiarly popular Condorcet loser who has
>fewest people who prefer someone else to him. Not only is it unlikely for
>Condorcet Loser, but suppose one did. It would be unaesthetic to elect a 
>Condorcet loser, but how disastrous would it really be to elect a
>over whom fewest people prefer someone else? Would Hitler, Bush, or David 
>Duke win MMPO? 

	Who knows. It's not clear how this question supports your argument. 
	Yes, failure of MMC and CL might be pretty rare in MMPO. But why on earth
should we chance it when methods that pass MMC and CL use the same ballots
and are just as easy to promote? If we're able to get beyond IRV, then why
not use SD, Smith//minmax, beatpath, ranked pairs, river, etc.? 
	There is no need to implement MMPO instead of SD. SD is just as easy to
explain, it's Smith efficient, MMC efficient, CL efficient, and Condorcet
efficient. I don't know how to quantify IC failure, but I know that MMPO's
IC failure is worse than SD's IC failure. Trading Smith, Condorcet, MMC,
and CL for FBC and later-no-harm is a lousy trade.

James Green-Armytage

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