• chaogomu@lemmy.world
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    1 month ago

    IRV, or RCV as it’s being sold here, has a lot of problems.

    It’s the only voting system in existence where ranking someone higher on the ballot can cause them to lose the election.

    Australia gets around most of the problems of IRV by just not telling people any information about the vote except the winners.

    Also you only use straight IRV for a single part of your government.

    The US would use it for every part of our government. It would be a shit show.

    Which is why RCV has been banned in half a dozen states.

    Now, there are better voting systems. Systems that live up to the hype.

    STAR is the single best voting system designed to date.

    As a cardinal voting system, it’s actually immune to the Spoiler Effect.

    • dan@upvote.au
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      1 month ago

      It’s the only voting system in existence where ranking someone higher on the ballot can cause them to lose the election.

      Interesting… Do you have an example of this?

      • chaogomu@lemmy.world
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        1 month ago

        https://medium.com/@Gbgrow/understanding-non-monotonicity-in-ranked-choice-voting-and-how-to-prevent-it-55ad54fdad06

        https://electionscience.org/research-hub/the-limits-of-ranked-choice-voting

        https://en.wikipedia.org/wiki/Negative_responsiveness_paradox#Specific_examples

        We’ve seen it happen in actual elections, as shown in the Wikipedia link.

        RCV is just a flawed system, which is expected for something created by a couple of guys 150+ years ago.

        • Sludgeyy@lemmy.world
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          1 month ago

          Disclaimer: I wrote this all for myself not to change your mind or argue. Helps if I write down my thoughts and I don’t see a problem sharing. Feel free to discuss if you like.

          35 voters: Alice > Carol > Bob

          35 voters: Bob > Carol > Alice

          30 voters: Carol > Alice > Bob

          Vs.

          41 voters: Alice > Carol > Bob

          29 voters: Bob > Carol > Alice

          30 voters: Carol > Alice > Bob

          Alice wins

          Vs.

          Carol wins

          Say you have:

          41 voters: Republican > Third-party > Democratic

          29 voters: Third-party > Democratic > Republican

          30 voters: Democratic > Third-party > Republican

          If those 29 voters couldn’t vote Third-party they would vote Democratic. So when the Third-party candidate is knocked out, their votes should favor their second pick. Democratic wins 59-41.

          If it was:

          41 voters: Republican > Third-party > Democratic

          29 voters: Third-party > Republican > Democratic

          30 voters: Democratic > Third-party > Republican

          Which makes more since on why the 6 votes moved to Republican because Republican was their second choice.

          Then Republicans win 70-30.

          In America you’d have 4 basic senarios

          25 voters: Republican > Third-party > Democratic

          25 voters: Third-party > Democratic > Republican

          25 voters: Third-party > Republican > Democratic

          25 voters: Democratic > Third-party > Republican

          In RCV, Third-party wins.

          Let’s say this

          30 voters: Republican > Third-party > Democratic

          25 voters: Third-party > Democratic > Republican

          20 voters: Third-party > Republican > Democratic

          25 voters: Democratic > Third-party > Republican

          Third-party still wins

          40 voters: Republican > Third-party > Democratic

          10 voters: Third-party > Democratic > Republican

          10 voters: Third-party > Republican > Democratic

          40 voters: Democratic > Third-party > Republican

          It would be a tie

          45 voters: Republican > Third-party > Democratic

          10 voters: Third-party > Democratic > Republican

          5 voters: Third-party > Republican > Democratic

          40 voters: Democratic > Third-party > Republican

          It would still be a tie

          45 voters: Republican > Third-party > Democratic

          5 voters: Third-party > Democratic > Republican

          10 voters: Third-party > Republican > Democratic

          40 voters: Democratic > Third-party > Republican

          Republicans win

          Let’s change it to this:

          35 voters: Alice > Carol > Bob

          35 voters: Bob > Alice > Carol

          30 voters: Carol > Alice > Bob

          Vs.

          41 voters: Alice > Carol > Bob

          29 voters: Bob > Alice > Carol

          30 voters: Carol > Alice > Bob

          Alice wins

          Vs.

          Alice wins

          They couldn’t make their whole point if you just switched Alice and Carol. And it makes much more sense that someone with Alice second would change it to Alice first.

          But when 29 votes still hold Alice as last, it does have some weight.

          Something just seems off about it and it’s because they cherry picked a senario that would work for their point.

          Alice > Carol > Bob

          Alice > Bob > Carol

          Bob > Alice > Carol

          Bob > Carol > Alice

          Carol > Alice > Bob

          Carol > Bob > Alice

          There are 6 ways to vote and they leave out half of them. Then they make Carol supporters favor Alice as their second choice.

          20 voters: Alice > Carol > Bob

          15 voters: Alice > Bob > Carol

          15 voters: Bob > Alice > Carol

          20 voters: Bob > Carol > Alice

          20 voters: Carol > Alice > Bob

          10 voters: Carol > Bob > Alice

          Carol eliminated, +10 Bob +20 Alice. Alice would win.

          If 5 voters from Bob > Alice > Carol were moved to Alice > Bob > Carol

          20 voters: Alice > Carol > Bob

          20 voters: Alice > Bob > Carol

          10 voters: Bob > Alice > Carol

          20 voters: Bob > Carol > Alice

          20 voters: Carol > Alice > Bob

          10 voters: Carol > Bob > Alice

          Alice would win

          What if everyone from Bob > Alice > Carol moved to vote for Alice > Bob > Carol

          20 voters: Alice > Carol > Bob

          30 voters: Alice > Bob > Carol

          0 voters: Bob > Alice > Carol

          20 voters: Bob > Carol > Alice

          20 voters: Carol > Alice > Bob

          10 voters: Carol > Bob > Alice

          It would be a tie.

          In bold are the three they selected:

          20 voters: Alice > Carol > Bob

          15 voters: Alice > Bob > Carol

          15 voters: Bob > Alice > Carol

          20 voters: Bob > Carol > Alice

          10 voters: Carol > Alice > Bob

          20 voters: Carol > Bob > Alice

          5 voters from Bob > Carol > Alice moved to Alice > Carol > Bob. Just like their example.

          26 voters: Alice > Carol > Bob

          15 voters: Alice > Bob > Carol

          15 voters: Bob > Alice > Carol

          14 voters: Bob > Carol > Alice

          10 voters: Carol > Alice > Bob

          20 voters: Carol > Bob > Alice

          Alice 41

          Bob 28

          Carol 30

          Bob is eliminated.

          15 votes goes to Alice. 14 goes to Carol.

          Alice still wins.

          But they set it up like:

          20 voters: Alice > Carol > Bob

          15 voters: Alice > Bob > Carol

          0 voters: Bob > Alice > Carol

          35 voters: Bob > Carol > Alice

          10 voters: Carol > Alice > Bob

          20 voters: Carol > Bob > Alice

          5 voters from Bob > Carol > Alice moved to Alice > Carol > Bob. Just like their example.

          26 voters: Alice > Carol > Bob

          15 voters: Alice > Bob > Carol

          0 voters: Bob > Alice > Carol

          29 voters: Bob > Carol > Alice

          10 voters: Carol > Alice > Bob

          20 voters: Carol > Bob > Alice

          Then when Bob is eliminated all 29 votes go to Carol.

          Then they say “It’s unfair that Carol wins”. When in reality those 29 people would prefer Carol over Alice.

          RCV might have some flaws but that article has some flaws.

          I haven’t looked at the others. I might later.

          Edit:Formatting

          • chaogomu@lemmy.world
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            1 month ago

            The first article is from someone who wants to save RCV, despite that one flaw that they’ve drilled into.

            The problem is that it’s a known attack vector, the Wikipedia article talks about how it was used intentionally by a political party in 2005 in Germany to effectively steal an additional seat in their parliament.

            My second link is a deeper dive into more of RCV’s many flaws. Because why stop at monotonicity? Seriously, the fact that increasing support can cause a candidate to lose, and not just lose but elect the worst choice, is insane.

            That fact that there are more flaws, just as game breaking, means we should all follow the example of the Marquis de Condorcet, the guy who invented RCV, abandoned it because he saw how broken it was.

            Then you have the lying liars at FairVote saying that the Condorcet criterion doesn’t matter in elections.

            The Condorcet criterion is that if you were to hold a series of one on one elections between all candidates, the winner of those should be the same winner of your election system. RCV fails this in most elections, which is why Condorcet abandoned it.

            It wasn’t until about 30 years after Condorcet’s death that an Englishman revived the voting method, but added a proportional twist. It still had all the flaws that Condorcet wrote about, but Condorcet was French, and lost the political games of the French Revolution, so he was mostly ignored.

            As a side note, the political writings of Condorcet should be required reading. The guy wrote this in 1790

            ‘The rights of men stem exclusively from the fact that they are sentient beings, capable of acquiring moral ideas and of reasoning upon them. Since women have the same qualities, they necessarily also have the same rights. Either no member of the human race has any true rights, or else they all have the same ones; and anyone who votes against the rights of another, whatever his religion, colour or sex, automatically forfeits his own.’

        • dan@upvote.au
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          1 month ago

          Thanks for the links. I appreciate it! Now I understand the issue.