[EM] Defeat Strength Demystified

Forest Simmons forest.simmons21 at gmail.com
Thu Sep 16 19:09:08 PDT 2021

I should have said "resistant" rather than immune.

To me immunity implies no defensive move needed, while (again, to me)
resistant means that you can thwart the threat without need of any drastic
action like an insincere order reversal.

If everybody who prefers the sincere CW over the Burial attacker truncates
that attacker,  that attacker should not win.

I have to confess that I never did become an expert in the taxonomy of
Condorcet defense criteria because I was more interested in other aspects
of election methods. Remember Demorep? He never took his eye off of the
Approval Completed Condorcet ball. It always appealed to me because I like
Approval more than Condorcet in many ways, and even though approval
strategy may seem daunting to some people, I never thought that optimal
approval strategy gave a better social utility result than naive gut
feeling approval, especially when no Condorcet candidate was agreed upon.

Here's an example where the Condorcet winner is obvious, yet imho the naive
Approval winner is better:

Sincere gut feelings:
45 A>C>>B..
55 B>C>>A...

I believe that C is a better compromise than  B who is the
Condorcet/majority, optimal rational strategy, Nash equilibrium, etc winner.

That's why I am more interested in lottery methods that make the sure
lottery 100%C the game theoretic unanimous lottery winner ... more than
refining deterministic methods.

Having said that, it is hard to stand by and say nothing when inferior
complicated methods are proposed in place of simple good methods like
Eppley's proposal of Ranked Pairs.

And I would hate to see that proposal get scuttled because of its weakness
vis-a-vis Chicken attacks ... hence my essay showing why it is vulnerable
and why not much can be done about that vulnerability strictly within the
confines of Universal Domain.

Demorep was looked upon condescendingly partly because he was socially
inept and partly because he insistently and unapologetically advocated a
simple method that violated Universal Domain.

And yet we now know that kind of violation is unavoidable in one way or
another for a truly satisfactory voting method.

Three Cheers for Demorep!!!

El jue., 16 de sep. de 2021 2:28 a. m., Kristofer Munsterhjelm <
km_elmet at t-online.de> escribió:

> On 9/16/21 6:09 AM, Forest Simmons wrote:
> > Eventually Mike O. went on to bigger and better things but a few years
> > ago he made a brief, but passionate, return to the EM List when the
> > Possibilities of Hope seemed to include a real possibility of election
> > reform.  As we weighed the merits of various methods it suddenly became
> > apparent that we didn't have a Condorcet method that was immune to both
> > burial abd "Chicken," a ploy that had not concerned us much in the past
> > but now loomed larger.
> >
> > O course IRV came up as a method that was immune to both Burial and
> > Chicken, but at the expense of the Condorcet Criterion.  A flurry of
> > activity on the EM list searched for a hybrid between IRV and Condorcet
> > similar to what we have seen since the resurrection of IRV as RCV.
> Just a note: No Condorcet method can be completely immune to burial. I
> think Chris Benham showed this, though I can't find the post where he
> did so. So it's then clear that no Condorcet method can be completely
> immune to both burial and chicken, either.
> I think my fpA-fpC is immune to chicken (but not burial). Of course,
> that's just a three-candidate method.
> -km
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