[EM] Approval-enhanced IRV (take 2)

[Forest Simmons]

On Mon, Aug 21, 2023, 9:36 AM C.Benham <cbenham at adam.com.au> wrote:

>
> This is I think more appealing and streamlined than my earlier version.
>
> *Voter strictly rank from the top however many candidates they wish.
>
> Also they can mark one candidate as the highest ranked candidate they
> approve.
>
> Default approval is only for the top-ranked candidate.
>
> Determine the IRV winner.
>
> On ballots that approve the IRV winner, approval for any candidate or
> candidates
> ranked below the IRV winner is withdrawn.
>
> Elect the pairwise winner between the (thus modified) approval winner
> and the IRV
> winner.*
>

So if a voter was giving out to much approval by approving below one of the
mandatory semi-finalists, the method fixes that faux pas for free!

What if the approval cutoff were simply moved adjacent to the IRV winner?

That would probably give the IRV winner's strongest defeater too much help,
and wrest too much control of the approval lever from the sovereign voters.

 It looks like you are treating the malady with the minimal effective dose
of the right medicine!

Great!

Who will spread the good news?

>
> This works fine in the same way as the earlier version in the example
> given to talk
> about Minimal Defense and Chicken Dilemma.
>
> It is more Condorcet efficient than normal IRV, and meets (or comes
> close enough
> to meeting) appropriately modified versions of the LNHs and Minimal Defense
> and Chicken Dilemma.
>
> 49 A  (sincere might be A>B)
> 24 B   (sincere might be B>C)
> 27 C>B
>
> If the C voters B>A preference is strong they can by approving B avoid
> regret for not
> Compromising.
>
> Then the final pairwise comparison will be between B and A and B will win.
>
> But if they are more concerned about not letting the B voters steal the
> election from
> them by possible Defection strategy then they can do that by not
> approving B.
>
> 49 A>C>>B
> 48 B>>C>A
> 03 C>A>>B
>
> Say this is for a seat in Parliament, and the voters have been
> accustomed to using FPP,
> IRV or Top-Two Runoff. It would cross the mind of no-one that the
> "Condorcet winner"
> C should defeat the IRV (and FPP and even Approval) winner A.
>
> But according to Condorcet advocates the B voters should or could be
> regretting not
> getting an outcome they somewhat prefer by all top voting C.
>
> Well with this system the B and C voters together can "fix" this without
> anyone betraying
> their favourites or reversing any sincere preferences simply by all of
> them approving C and
> not A.  Then the final pairwise comparison will be between C and A with
> C winning.
>
> Chris Benham
>
>
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