Talk:IRV Prime: Difference between revisions
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Hello, Condorcet and Later-no-harm are incompatible - see proof in Woodall.<ref name="Woodall-Monotonicity">D R Woodall, [http://www.votingmatters.org.uk/ISSUE6/P4.HTM "Monotonicity and Single-Seat Election Rules"], ''[[Voting matters]]'', Issue 6, 1996</ref> Could you run your method through the example provided there and update the article? |
Hello, Condorcet and Later-no-harm are incompatible - see proof in Woodall.<ref name="Woodall-Monotonicity">D R Woodall, [http://www.votingmatters.org.uk/ISSUE6/P4.HTM "Monotonicity and Single-Seat Election Rules"], ''[[Voting matters]]'', Issue 6, 1996</ref> Could you run your method through the example provided there and update the article? |
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[[User:Kristomun|Kristomun]] ([[User talk:Kristomun|talk]]) 09:12, 31 July 2021 (UTC) |
[[User:Kristomun|Kristomun]] ([[User talk:Kristomun|talk]]) 09:12, 31 July 2021 (UTC) |
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So if you look at [https://www.rangevoting.org/Woodall97.pdf Woodall's full paper], he does not say they're incompatible: |
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In general, CONDORCET is incompatible with LATER-NO-HELP, LATER-NO-HARM, |
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MONO-RAISE-DELETE, MONO-SUB-PLUMP and, in the presence of PLURALITY, MONO-ADD-TOP. |
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"in general" |
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--[[User:Marcosb|Marcosb]] ([[User talk:Marcosb|talk]]) 22:39, 3 August 2021 (UTC) |
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== Arrow/IIA == |
== Arrow/IIA == |
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Who wins in IRV Prime? If it's A, then eliminating B (irrelevant candidate) should make C win by majority rule. If it's B, then eliminating C makes A win; and if it's C, then eliminating A makes B win. I may be missing something, though! :-) [[User:Kristomun|Kristomun]] ([[User talk:Kristomun|talk]]) 22:22, 31 July 2021 (UTC) |
Who wins in IRV Prime? If it's A, then eliminating B (irrelevant candidate) should make C win by majority rule. If it's B, then eliminating C makes A win; and if it's C, then eliminating A makes B win. I may be missing something, though! :-) [[User:Kristomun|Kristomun]] ([[User talk:Kristomun|talk]]) 22:22, 31 July 2021 (UTC) |
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Running through the IRV-Prime steps, first we do classic IRV, which eliminates C & finds winners={A}: |
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A: 60 |
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B: 30 |
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We now see if any candidate can win against A (we know B can't), i.e. WinnersPrime={C}: |
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C: 55 |
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A: 35 |
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And as such C is the winner in IRV-Prime; this is a classic case of A=Rock, B=Scissors, C=Paper; if I phrase it to you as "suppose B & C voters were to go up against A: which candidate should they stand behind?" |
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--[[User:Marcosb|Marcosb]] ([[User talk:Marcosb|talk]]) 22:39, 3 August 2021 (UTC) |