On Jul 25, 2005, at 01:24, Dave Ketchum wrote:
"Strategically" still turns me off. Voters who preferred B over A, and had planned to vote accordingly, are gambling that they can get better results by claiming, instead, to prefer A over B: In some cases they can, unfortunately, succeed at what they claim to want. If these can change their votes, then so can others for other reasons, thus destroying the knowledge all used in plotting. How cycles operate was used in the plotting. Cycles are valuable in resolving near ties, but deliberately setting them up for intended results is tricky.
My thoughts around the pair-wise comparison based voting methods and strategies are roughly as follows. Rating based methods are maybe too vulnerable to strategies in contentious elections, so we may have to satisfy with ranking based methods. Pair-wise comparison methods are a wonderful solution that allows voters to express their preferences quite extensively (but still easily) and in most cases without any strategy problems. Sincere voting thus seems to pay off (better than in many currently used election methods). Unfortunately we have the cycle related problems (otherwise the methods would be quite flawless). Natural cycles are luckily quite rare. Artificially generated cycles are a bigger problem. The big question is if pair-wise methods are still good enough to be recommended for use. I think the differences between different tie breaking methods are not that big. Since all of the pair-wise comparison methods have some of the basic vulnerabilities, the more important question seems to be if the pair-wise comparison methods are useful in general as a group. In real election situation also the real life environment has an influence. If majority of the voters vote sincerely, the strategic voting problem remains just as background noise in the process without causing any considerable harm (((hmm, the example I presented studied the the possibility that very few strategic votes could pick a "bad winner"...))). If the method and attitudes of voters are bad enough, then strategic voting might be a problem. And if the impact of strategic voting would be worse than what currently used election methods have (e.g. some really bad candidates would be elected), then we would need to deem pair-wise election methods unusable (is some environments?) and would be forced to go back to (recommending) some simpler election methods (e.g. IRV, two round runoff, plurality, approval). So far I'm leaning in the direction that strategic voting would at least in large public elections be marginal (or done mostly by voters who didn't know that in the new method they don't need to vote strategically but the a sincere vote is likely to defend their interests in the best possible way). I'm also leaning in the direction that voting methods that pick the best winner could be more useful than ones that aim at eliminating strategies. Partly because people want the method to provide best possible results, partly because the strategic fixes may be marginal, partly to keep the method simple and understandable, and partly because strategic countermeasures easily lead people to thinking that strategic voting is a key property of the method. I'm not 100% sure that the simplest methods work fine and I'm still waiting for someone to prove that some methods are unusable and some usable (but haven't seen (or understood :-) that yet). So, for me the question is if the basic pair-wise comparison methods are strategy free enough to be used as practical election methods as they are. And my guess is, yes they are in most single winner elections.
But here the example you constructed resulted in a win by the plotters in wv - and in the result they claimed to want, but which was worse for them than what they would have achieved without plotting, under margins.
Yes, based on this single isolated example one should recommend margins based methods and not winning votes based methods. I in general do like margins also since they seem to be a more natural measure of preference than winning votes, so this result is just fine for me :-). Winning votes have maybe some burden of being overloaded with hopes of finding a panacea in the fight against strategic voting.
Best Regards, Juho ---- Election-methods mailing list - see http://electorama.com/em for list info
