[EM] Detailed stats for the ordinal methods

[Closed Limelike Curves]

Hi Kristofer! Thanks for this :)

I do want to ask though, do you think the rate of manipulable elections
is a good measure of the "general strategy resistance" of an electoral
method? The resistant set certainly seems to reduce that rate, but for all
I know that 7.5% is all turkey-elections.

On Thu, May 9, 2024 at 10:49 AM Kristofer Munsterhjelm <km_elmet at t-online.de>
wrote:

> On 2024-05-09 18:08, Richard, the VoteFair guy wrote:
> > Bravo Kristofer!  Thank you for doing these valuable calculations!!
> >
> > IMO it reveals two important points:
> >
> > * The methods that get the highest resistance to strategic/tactical
> > voting are methods that combine pairwise vote counting with IRV-style
> > counting.  Specifically the lowest failure rates are for:
> >
> > ** RCIPE (IRV with pairwise eliminations)
> > ** Benham (IRV except stop when pairwise winner)
> > ** Smith-IRV (Woodall)
> > ** Schwartz-IRV (Schwartz-Woodall)
> > ** IRV.
>
> In particular, strategy resistance seems to be linked to the resistant
> set I defined last year. https://electowiki.org/wiki/Resistant_set
>
> Here's a rough example showing just that, with Resistant,Borda. 5k
> elections so it won't take so long to calculate, but the other details
> are as in my previous simulations: 99 voters, 4 dimensions, and 4
> candidates:
>
>     Ties: 0.001 (5)
>     Of the non-ties:
>
>     Burial, no compromise:        123     0.0246246
>     Compromise, no burial:        72      0.0144144
>     Burial and compromise:        147     0.0294294
>     Two-sided:                    48      0.00960961
>     Other coalition strats:       1       0.0002002
>     ================================================
>     Manipulable elections:        391     0.0782783
>
>     Worked in 391 (0.0752, 0.0828) out of 4995 for [Inner burial
> set],[ER-Borda] ties: 5
>
> Going from 0.70 to 0.08 by restricting to a particular set is pretty
> respectable.
>
> The IRV hybrids you listed elect from the resistant set because they
> pass a "proper order criterion": if X disqualifies Y, then X is never
> eliminated before Y.
>
> I don't quite know *why* electing from the resistant set seems to grant
> general strategy resistance. I've only been able to prove burial
> resistance, though in practice it limits other strategies too.
>
> -km
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