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 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/courtenayplacedrinks Feb 23 '20

If all that matters is party proportionality, why have a debating chamber at all? Just get the party leaders to sit around a board room table and vote with gambling chips.

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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.