Mike wrote: > Ok, winning in violation of majority rule, by truncation, in the way that > can happen in margins methods--how will that happen in wv methods > by flipping a coin?
Say a voter's sincere vote is A>B>C and he could gain some advantage under margins by insincerely voting A>B=C. Under winning-votes, all he has to do is flip a coin. If it's heads, he votes A>B>C; if it's tails, he votes A>C>B. Doing this gives him exactly the same expected outcome as would voting A>B=C under margins. Besides, generally, when voting A>B=C would help, voting A>C>B would help even more, which would work just fine under winning-votes. As Blake has put it before, winning-votes is "easy to get around". Now one might say that voters will be too dumb to flip a coin or too principled to engage in strategic reversal. Fair enough. If I were sure of that, I'd probably support winning-votes too, despite its lower social utility. But like I've said, I prefer to be pessimistic and realize that voters will likely catch on. > When you said that wv doesn't guarantee anything that margins > doesn't guarantee, I told you of some guarantees, which I call > SFC & GSFC. Yes, and Blake and I have explained patiently why, in our opinions, those guarantees are ultimately useless, even if they sound attractive. > In CSSD(wv), BeatpathWinner(wv), or Ranked-Pairs(wv), > if X is in the sincere Smith set, and Y is not, and if a majority > prefer X to Y, and vote sincerely, and if no one falsifies a preference, > then Y can't win. Not even if someone flips a coin :-) Sure, if no one "falsifies a preference". Which means it's okay for them to vote insincere ties (like A>B=C) but not to reverse (like A>C>B). But I'd say voting A>B=C is insincere just as A>C>B is, if a little less extreme. According to your definition, voting A>B=C isn't falsifying a preference, but voting 50% A>B>C and 50% A>C>B is. And what if every voter is willing to vote strategically (which is obviously the kind of case I'm most interested in)? Your guarantees don't mention that case at all. > Yes, I know that you think that, with wv, voters who'd otherwise > have only truncated would order-reverse. Even if the necessary number > of people were inclined to do that, which is really doubtful, it > would carry a great danger of backfiring. Perhaps, but strategic reversal is no more dangerous in winning-votes than in margins, so that's also an argument for not worrying about strategic reversal under margins. I personally would vote sincerely in a Condorcet election unless I could somehow be *really* sure that a reversal would be to my advantage (except maybe for voting high ties if a winning-votes method were used). > If the insincere voting that you're referring to is ranking in > different rank positions candidates whom you sincerely rate equally, > do you really think that's important? That's not what I actually had in mind, but sure, I think it's important. I see voting preferences you don't have as insincere. Having said that, unless there are two candidates who are literally clones of each other and exact in every way, I think the only possible reason for not preferring one to the other is laziness. > Rob LG, if you'll check the introductory web-page for EM, it points > out that it isn't productive to repeat refuted arguments. We've been > over all this before. Obviously I don't believe that my arguments have been refuted. I think Blake and I have done a good job refuting your arguments. But in the end it comes down to assumptions we prefer to make. I don't see truncation as a case of insincere voting to be treated specially, and I don't see winning-votes's handling of tied preferences as doing any good if the voters are informed, as I've explained. > Yes, it isn't an offensive strategy that works. It won't steal > the election from a sincere CW, or violate majority rule in the > way that I've pointed out that margins will. Again, winning-votes's guarantees only hold when no voter "falsifies a preference". Pretty fragile. > As for flipping coins, that of course would most likely have no > effect in a public election, as the coin-flips and the resulting > AB votes would tend to cancel out. Exactly. Under winning-votes, a bunch of voters voting half A>B>C and half A>C>B will get the same result as if they had all voted A>B=C under margins. If they benefit from the insincerity, then winning-votes's guarantees are rendered ineffective. Winning-votes works only when voters are stupid enough not to realize that they have just as many strategic options as under margins; in fact, they have more, since margins allows no equivalent to winning-votes's A=B>C. > "Every method has problems, and so we shouldn't try to minimize > the magnitude of the problems"--That sounds like what we hear > from our IRV friends. That isn't at all what I said. Of course I think we should minimize problems created by strategy. I pointed out how winning-votes shares every single strategic problem that margins has when voters aren't ignorant, and noted that *any* ranked-ballot method will have serious strategy problems when the electorate is well-informed and there is no sincere Condorcet winner. All we can do is to try to minimize them, which is difficult. Mike is comforted by the fact that winning-votes methods make it easier to protect a sincere Condorcet winner when no voter reverses strategically. I'm not. He wants to prevent offensive "truncation". But as I've explained, a voter could make his offensive "truncation" just as effective (game-theoretically equivalent) under winning-votes as under margins, whether by randomization or coordination. If you don't agree, if winning-votes makes guarantees that are still important to you, then you're right to prefer winning-votes. I don't say it's wrong. But if you agree with me that winning-votes is actually "easy to get around", then margins makes more sense, being better at social utility and arguably more intuitive for the voter. I don't expect to convince Mike. If I'd done all the work he has on Condorcet methods, I'd be proud too, and I have the highest respect for his objective approach to evaluating methods. I've just tried to explain how *my* reasoning leads me to reject winning-votes as (as we say in Texas) all hat and no cattle. -- Rob LeGrand [EMAIL PROTECTED] http://www.onr.com/user/honky98/rbvote/calc.html __________________________________________________ Do You Yahoo!? Yahoo! Tax Center - online filing with TurboTax http://http://taxes.yahoo.com/
