[EM] Fwd: Election-Methods Digest, Vol 236, Issue 18

[robert bristow-johnson]

> On 03/16/2024 9:11 PM EDT Closed Limelike Curves <closed.limelike.curves at gmail.com> wrote:
> 
> 
> > We don't wanna burden voters with any pressure to vote tactically, do we? Why are people (equal.vote (http://equal.vote/), CES) promoting methods that, whenever there are 3 or more candidates, **inherently** forces voters to make tactical consideration of how they're going to vote for their 2nd-favorite candidate?
> Every method does this. With 3 candidates all Condorcet methods can encourage burial.

Only if there is a cycle involved.  Either the election was in a cycle in the first place or if the burial strategy is to push the election into a cycle.

If there never ever were any cycles, then Condorcet does not fail.  No spoiler, no incentive to vote other than sincerely.  If you (the voter) lose, it's because you're in the minority.  If your hated candidate wins, it's because no other candidate is favored by more voters than this hated candidate.

> > BTW, I posted at r/EndFPTP a derived scenario that shows how STAR fails to disincentivize tactical voting, even with the head-to-head runoff. https://www.reddit.com/r/EndFPTP/comments/1bbq6hu/heres_a_good_hypothetical_for_how_star_fails/
> I don't see how that's a failure. There's two possibilities here:
> 1. If the votes are honest, I don't see what the problem is. The three candidates are neck-and-neck and there's not much reason to prefer any.

The Center candidate is the Condorcet Winner and STAR *only* compares relative *rankings* in the runoff.  So like IRV, if the Condorcet Winner gets into the final runoff, the Condorcet Winner will always beat anyone else there.

The voters supporting Center but who liked Left better than Right would have done better (like get their candidate elected) by burying Left.  (But at least 6 of them, had 4 of them buried Left, they would cause Right to win.)  So, by even by scoring Left at merely 1, they actually betrayed their favorite candidate.

The voters supporting Right and who liked Center better than Left (this would be normal) would have done better (like preventing Left from winning) by scoring Center a little higher than they did.  Had 2 or 3 or 6 of them scored Center higher, enough for 6 points, then Left would be defeated.  But then they have to betray their favorite candidate and the promise of STAR is that you don't have to do that.  Now, what was hard for the Right voters in Burlington to accept was that their candidate was never going to win in *any* pairwise comparison and that their candidate was the spoiler. But that was actually the case.  Alaska was a little different.  Peltola was always in the lead and there was no "come from behind" victory as occasionally happens with IRV.

> 2. If the votes are strategic, this seems like terrible strategy on the part of each group.

NO VOTER should have to strategize.  But I explained that if your preference is A>B>C, why without sophisticated consideration of the possibilities it makes perfect sense to score your ballot A:5, B:1, C:0.  Makes simple sense, particularly with STAR (and assuming only 3 significant candidates).  The problem is when it's a close 3-way race, then, whether it's STAR or IRV, then tactical voting might serve a voter's political interests better than sincere voting.  We should prevent that burden of tactical voting whenever we can.  (And we can with the ranked ballot as long as there is always a Condorcet Winner.)

> Why wouldn't you give the center candidate more than 0 stars?

I modeled this after real votes in Burlington 2009.  There were 1289 Right voters (outa 3294) that bullet-voted for Right.  There were even 568 Left voters (outa 2981) that bullet-voted for Left.  That's what they did.

Now, unlike STAR, IRV would not have helped the Center voters with any burying strategy.  The problem with both STAR or IRV is with the Right voters who were told that they can throw their full support behind Right and not get burned by it.  That was clearly not true in Burlington 2009 nor in Alaska 2022 with IRV and I don't think STAR would have done better.

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r b-j . _ . _ . _ . _ rbj at audioimagination.com

"Imagination is more important than knowledge."

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