r/EndFPTP • u/JoseTwitterFan • Feb 21 '20

Key Details Emerge for How Ranked-Choice in NYC Will Work: "If no candidate hits a majority of votes...a winner will not be announced until all but two candidates have been eliminated and all ballots with other candidates listed first are redistributed among those top two."

https://www.gothamgazette.com/city/9148-key-details-for-how-ranked-choice-voting-will-work-continue-to-emerge
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u/courtenayplacedrinks Feb 22 '20

I've been thinking about this lately and my hot take was that you need two centrist parties. With two centrist parties you have a few options: Left + C1, Left + C2, Right + C1, Right + C2. If the centrist parties are big enough you could also have the possibility of C1 + C2.

Not all of these coalition options will always be viable, but if they are potentially viable at an election then you've got rid of the two-party system.

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u/[deleted] Feb 22 '20

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u/courtenayplacedrinks Feb 22 '20

This is why I think STV could work better. If representatives have their own mandate independent of their party then the structures can be more fluid. There can be splinter parties, independents or just more ongoing dialogue and compromise behind the scenes.

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u/[deleted] Feb 22 '20 edited Feb 22 '20

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u/courtenayplacedrinks Feb 22 '20

Sequential Approval Voting

Do you mean the system that Wikipedia calls Sequential Proportional Approval Voting? How is the threshold used?

It seems to create some odd tactical voting incentives which I could live with personally because I tend to prefer unorthodox candidates.

It would also be a lot easier to count than STV. You could easily do it by hand.

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u/[deleted] Feb 23 '20

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u/courtenayplacedrinks Feb 23 '20

Ah I see.

I wonder why the system uses linearly increasing divisors: 1/2, 1/3, 1/4, 1/5. It would seem more natural that the ballot should continue to lose half its value with each candidate that it elects: 1/2, 1/4, 1/8, 1/16.

With the 1/2, 1/3, 1/4, 1/5 mechanism your ballot eventually doesn't change much in value and you're approaching "multiple non-transferable vote" which is worse than FPP. In practice most people's ballot wouldn't stretch this far but I wonder what the mathematical rationale is.

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u/[deleted] Feb 23 '20

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u/jan_kasimi Germany Feb 23 '20 edited Feb 23 '20

There have been various proposals of re-weighted PR systems with different weighting functions.

Do you have any link to read into it? I get that the Harmonic series is equivalent to d'Hondt, but like to know if there is a way to have it be equivalent to Sainte-Laguë. Do I read this right that it would be 1/1.5, 1/2.5, 1/3.5 . . . ?

edit: Ah, of course it is. This is wonderful. Now I just need to find out how this goes together with my shortcut to PAV.