4 ms·
Arrow's theorem only applies to ranked ballots. But there's another concept that still shows how nothing can be perfect. But really, the question isn't whether
by quadrangle 8y ago
Arrow's theorem only applies to ranked ballots. But there's another concept that still shows how nothing can be perfect.
But really, the question isn't whether pathologies are possible ever, the question is how likely they are. What systems have the best balance to be the most robust while still being practical? STAR Voting and 3-2-1 voting. Definitely not IRV. IRV's pathologies have high enough probability that they do and will continue to show up significantly.
Good starting reference from one of the leading voting theorists:
https://www.quora.com/What-is-the-best-single-winner-voting-method-for-electing-presidents-mayors-or-other-executives https://www.quora.com/What-is-the-best-single-winner-voting-...
- bscphil 8y agoSTAR voting is good, but it makes the (IMO) mistake of taking the average rating as each candidate's score. I think it's absolutely crucial in a voting system to make it resilient to manipulation, and that means that taking the median rating (as in Majority Judgement) is the way to go.
- quadrangle 8y agoSTAR does NOT make that mistake. I mean, it literally doesn't. It uses the SUM of scores, NOT the mean or the median. But sum is effectively the same result as taking the median.
- dragonwriter 8y agoSum is effectively equivalent to mean, not median.
- quadrangle 8y agoWell, the main concern most people have with mean is if it ignores abstentions. Sum does not ignore abstentions, they are the same as a marked 0. But you're right that sum is like mean if mean counts all the abstentions as 0's. I'm open to the idea that actually using median is superior. Could you expound on that?
- gumby 8y agoYou're just picking one element. People have to understand and believe the system. A system in which you weigh the full set of a:b, a:c, b:c would be too tedious for anything but the board of the mathematical society. If we could only get those pesky humans out of the loop...but we don't.
- quadrangle 8y agoI don't understand why this follows my comment. I agree with you about that weighing challenge, about the humanity… But I don't know what you mean about "picking one element" or understanding or believing. Both STAR and 3-2-1 are quite understandable, believable, and don't require weighing full sets of pairings. That weighing you describe sounds like how Ranked Pairs version of ranked-ballots is done.