[EM] Kristofer: MMPO objections

fsimmons at pcc.edu fsimmons at pcc.edu
Thu Jan 5 13:34:25 PST 2012


I agree that Plurality failure is bad in a public proposal and hard to defend in any case.

In the case of MMPO the question is moot because Plurality failure is so easily fixed by either of the 
following natural tweaks:

1. Put 50 percent in each of the diagonal positions.  (A candidate would beat a clone of itself half of the 

2. Put the respective truncation totals down the diagonal positions. (These totals are the pairwise 
oppositions of the Minimum Acceptable Candidate.)

With this second fix, you can also create a list of oppositions against MAC, and if MAC's max 
opposition is smaller than any other candidate's max opposition, then various possible courses of action 
exist:  (a) throw out these candidates and start over. (b) elect the approval winner (i.e. the one with min 
opposition from MAC, which is the same as the one with most opposition against MAC). (c) use the fall 
back lottery to elect the winner.

> Date: Wed, 04 Jan 2012 17:16:26 +0100
> From: Kristofer Munsterhjelm 
> Cc: election-methods at electorama.com
> Subject: Re: [EM] Kristofer: MMPO objections
> On 01/04/2012 04:56 PM, Kristofer Munsterhjelm wrote:
> > The Plurality criterion isn't just failed by methods that 
> return an
> > un-Plurality-method-like result. It is also failed by methods that
> > return an un-Approval-like result. Recall that the Plurality 
> method says
> > "if A is ranked first on more ballots than B is ranked at all, B
> > shouldn't win".
> That should of course say the Plurality *criterion*. Sorry about that.

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