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This is completely false. Pretty much all voting systems are susceptible to tactical voting, e.g. gaming the vote. This was formally proven via the Gibbard–Satt
by typest 6y ago
This is completely false. Pretty much all voting systems are susceptible to tactical voting, e.g. gaming the vote. This was formally proven via the Gibbard–Satterthwaite theorem[1], which showed that the only way for a voting system to be ungameable was to either have a dictator (a certain special voter who always picks the winner), or to pre-constrain the output space to only two alternatives.
This critique certainly applies to Instant-Runoff Voting, the algorithm in question here. It is known that IRV often incentivizes voters to not rank their favorites first [2].
[1] https://en.wikipedia.org/wiki/Gibbard%E2%80%93Satterthwaite_theorem https://en.wikipedia.org/wiki/Gibbard%E2%80%93Satterthwaite_...
[2] https://electionscience.org/library/tactical-voting-basics/ https://electionscience.org/library/tactical-voting-basics/
- jefftk 6y agoGibbard–Satterthwaite only covers ordinal voting systems: it doesn't apply to, for example, approval voting.
- typest 6y agoYes, you are right. I should have written more carefully. I am a huge fan of approval voting. Anyone reading this -- you should look more closely at approval voting, which surpasses ranked choice voting in many ways. https://electionscience.org/library/approval-voting-versus-irv/ https://electionscience.org/library/approval-voting-versus-i...
- dane-pgp 6y agoNot only is Gibbard–Satterthwaite only applicable to ordinal voting systems, it is only applicable to single winner electoral systems. A popular example of a multi-winner system is STV[1], which I suppose could be used to elect a President and Vice President, similar to the situation in the US before the Twelfth Amendment was ratified.[2] [1] https://en.wikipedia.org/wiki/Single_transferable_vote https://en.wikipedia.org/wiki/Single_transferable_vote [2] https://en.wikipedia.org/wiki/Twelfth_Amendment_to_the_United_States_Constitution https://en.wikipedia.org/wiki/Twelfth_Amendment_to_the_Unite...