[EM] Endorsement for STAR voting

[robert bristow-johnson]

So I referred to an r/EndFPTP post, but I'll repeat it here.

So the STAR folks make claims of "STAR Voting eliminates vote-splitting and the spoiler effect so it’s highly accurate with any number of candidates in the race." It's just a falsehood.

It's also a falsehood to claim: "With STAR Voting it's safe to vote your conscience without worrying about wasting your vote." 

While it's a simple head-to-head election between the two STAR finalists in the runoff (the "R" in "STAR"), the issue is *who* are those finalists. Same problem as IRV.

So I derived a demonstration case from the Burlington 2009 election.  I just scaled it from 8900 voters to 100 and made very reasonable assumptions for how voters would score the candidates.  Remember with STAR, the maximum score is 5 and the minimum is 0.  To maximize their effect, a voter would score their favorite candidate with a 5 and the candidate they really don't want elected with a 0.  The big tactical question is: What to do with the third candidate that is neither my favorite nor my most hated candidate?

  L => Left candidate (who was Kiss in 2009)
  C => Center candidate (Montroll)
  R => Right candidate (Wright)

100 voters:
   
   - 34 Left supporters:
   --- 23 ballots: L:5 C:1 R:0
   ---  4 ballots: L:5 C:0 R:1
   ---  7 ballots: L:5 C:0 R:0
   
   - 29 Center supporters:
   --- 15 ballots: L:1 C:5 R:0
   ---  9 ballots: L:0 C:5 R:1
   ---  5 ballots: L:0 C:5 R:0
   
   - 37 Right supporters:
   --- 17 ballots: L:0 C:1 R:5
   ---  5 ballots: L:1 C:0 R:5
   --- 15 ballots: L:0 C:0 R:5

Now, in the final runoff, the Center candidate will defeat either candidate on the Left or Right, head-to-head.

Score totals:

 Left   = 34x5 + 15 +  5  = 190
 Center = 29x5 + 23 + 17  = 185
 Right  = 37x5 +  9 +  4  = 198

So who wins? With Score or FPTP, Right wins. With STAR or IRV, Left wins. With Condorcet, Center wins.

Now let's look more closely at STAR. Right and Left go into the final runoff. 49 voters prefer Left over Right, 46 voters prefer Right over Left, so Left wins STAR by a thin margin of 3 voters. But remember, head-to-head more voters prefer Center over either Left (by a 7 voter margin) or Right (by an 11 voter margin). Then what would happen if Center was a finalist in the runoff?

Now those 17 Right voters that had a 2nd-choice preference of Center over Left, what if 6 of them had scored Center a little higher? Like raised the score from 1 to 2? Or if 3 of them raised their scores for Center from 1 to 3? Or if 2 of them raised their scores for Center from 1 to 4? How would they like that outcome?

Or, more specifically, what if the 15 Center voters that had a 2nd-choice preference for Left, what if 6 of them had buried their 2nd-choice and scored that candidate (Left) with 0? How would they like that outcome?

This demonstrates (especially with very realistic election conditions in a *close* 3-way race) that, because of the Score aspect of STAR, voters need to be thinking tactically whenever there are 3 or more candidates.  They must worry about how high to score their 2nd-favorite candidate (or maybe a candidate they dislike less than the candidate they hate).  If they score that candidate wrong, they can cause their own candidate to lose or they can cause their hated candidate to win.

But with the ranked ballot, we know what to do with our 2nd-favorite candidate; We rank them #2.

BTW, Approval Voting (used in Fargo North Dakota despite a ruling from the ND Supreme Court in 1911 that would apparently prohibit it) is also a Cardinal method (Approval Voting is a degenerate case of Score Voting with only 0 and 1 as scoring levels).  The same tactical voting issue exists when there are 3 or more candidates: Does a voter serve their political interests best by Approving their 2nd-favorite candidate or not approving them?

Lastly, the question I can't get either the STAR or Approval proponents to answer, if the ranked ballots are enough to tell us that and how IRV failed in Burlington 2009 and Alaska 2022 (by not electing the Condorcet winner), why not just use the information provided in these ranked ballots to *not* fail to elect the Condorcet winner.  Why throw the baby out with the bathwater and bring in a completely different system that is also not guaranteed to elect the CW when one exists?  It doesn't make sense to me.

--

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

"Imagination is more important than knowledge."

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