> Date: Mon, 20 Dec 2004 21:59:38 +1030 > From: Chris Benham > Subject: [EM] MMPO, Majority, Condorcet failures
> To me the price MMPO (MinMax Pairwise Opposition) pays for strategy > benefits you describe is just far too high, > failing as it does (Mutual) Majority and Clone-Winner. (Also very > unattractive to me is that it combines meeting > Later-no-harm with failing Later-no-help, and thus having a > zero-information random-fill incentive.) > > A method that seems to perform as well in all your 3-candidate scenarios > with lots of lazy truncating voters, is > Raynaud(Gross) with the tiebreaker suggested by Gervase Lam. (It > could also be called Raynaud(opposing votes) > or Max Pairwise Opposition Elimination). > > This would fail Mono-raise, but at least meet Clone Independence and > (Mutual) Majority. So in my view it is much > better! What do you think? Mono-raise is Monotonicity isn't it? Monotonicity says that if a candidate X is lowered in the ranking in a ballot, it should not increase the chances of X winning. If Mono-raise is Monotonicity, then ouch! Forest's very recent posts on IRNR may also be worth referring to because Raynaud(Opposing Votes) is just applying MMPO and then eliminating the last placed candidate in each round. (Thread: Range Voting and Cardinal Ratings Runoff). As a consequence, I don't think Smith//MMPO is quite a good thing either. Monotonicity to me seems to be a very fundamental requirement for ranked election methods. If I had to choose between Clone Independence and Monotonicity, but not both, then I think I would go for Monotonicity. Just in case I don't read this list until next year, merry christmas everybody! Thanks, Gervase. ---- Election-methods mailing list - see http://electorama.com/em for list info