# [EM] MMPO

Forest Simmons fsimmons at pcc.edu
Sun Oct 2 16:26:18 PDT 2016

```Michael,

You have a good memory.

Zero to ten might be enough resolution for this technique to work for
typical levels of information.

Here's another criterion idea for use with Score style ballots:

We could say that candidate X strongly covers candidate Y iff X pairwise
beats every candidate that Y beats including the virtual candidates (if
any) that Y beats.

In particular, if Y beats a certain score level by having its median score
higher than that level, then so should X.

Forest

On Sat, Oct 1, 2016 at 3:16 PM, Michael Ossipoff <email9648742 at gmail.com>
wrote:

> Yes, avoiding the Plurality criticism could be worth requiring 1/8 of the
> A voters to truncate B.
>
> There could be an agreement between A & B voters, to rank eachother's
> candidate with 7/8 probability.
>
> "Flip a coin 4 times. If it comes down the same way every time, then don't
> rank them."
>
> That reminds me of the Srategic-Fractional-Support anti-defection
> strategy-suggestion that you made some time ago, & which I've been
>
> It's for methods without built-in chicken-dilemma protection, such as
> Approval.
>
> In one version, faction A could try to probabilistically give  faction B
> just enough votes to make B win if the B faction is bigger than the A
> faction believes itself to be.
>
> Sure, it's a guess, but the A faction's guess is as good as the B
> faction's guess. They both have access to the same predictive information.
>
> So the fact that the  A faction is trying that should deter defection by
> the B faction.
>
> It, too, could be done probabilistically, but it's one reason why I like 0
> to 99 or 0 to 999 Score voting.
>
> Also, in Approval, amicable factions could probabilistically give
> eachother's candidate some near-unity fraction of an approval. They're
> effectively fully helping eachother, but the bigger faction will
> automatically outpoll the other.
>
> Michael Ossipoff
>
> On Oct 1, 2016 12:09 PM, "Forest Simmons" <fsimmons at pcc.edu> wrote:
> >
> > Here's an idea for fixing MMPO's lack of  Plurality compliabnce:
> >
> > Include the opposition of the Implicit Approval Cutoff Candidate, the
> virtual candidate on the truncation boundary.
> >
> > Example:
> >
> > 40 A
> > 10 C>A
> > 10 C>B
> > 40 B
> >
> > In regular MMPO, the max opposition to C is 40.  But when the number of
> ballots on which C is truncated is counted among the oppositions, the max
> opposition becomes 80.  Thus Plurality is rescued.
> >
> > How about the Chicken problem?
> >
> > Consider
> >
> > 49 C
> > 3 A  (sincere A>B)
> > 24 A>B
> > 24 B (sincere B>A)
> >
> > Regular MMPO gives A the win contrary to Plurality.
> > Taking the truncation opposition into account we have max oppositions
> for A, B, and C, respectively, as  73, 52, and 51.  Candidate C wins,
> punishing B's defection.  This only required three of the A supporters to
> truncate B.
> >
> > Unfortunately, even this new version of MMPO fails Condorcet Loser and
> Clone Winner.
> >
> > ----
> > Election-Methods mailing list - see http://electorama.com/em for list
> info
> >
>
>
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