Jameson: > But the criterion's premise stipulates optimal voting. Voting to > maximize one's utility-expectation. That's extreme voting.
Unproven assertion. One which I believe is based on sound logic but faulty assumptions, and is therefore false. [endquote] Sure, the matter of what way of voting is optimal in MJ must come before any comparisons of frequency of Strong IIAC failure. You said that you'd rather stipulate realistic voting instead of optimal voting, in Strong IIAC's premise. But optimal voting, voting to maximize one's utility-expectation, is simply-defined. Defining realistic voting would be prohibitively difficult and subjective, for a criterion. Besides, realistically, people _do_ vote to maximize their utility-expectation, based on their assumptions and beliefs. Everything said by voters confirms that. Anyway, certainly, as you said, the first question is the question about what kind of voting is optimal in MJ. Until that is established, it would be premature to discuss how often the methods fail Strong IIAC. Are you sure that it's better for a method to less frequently violate Strong FBC? Why? ordinary IIAC, as I defined it, makes obvious sense, in terms of consistency and responsiveness. Even though it isn't crucially important, it still makes more sense to pass it than to fail it. But why would it be better for a method to less often fail Strong IIAC? Why shouldn't people make different choices, among a different candidate-set? You said: I would prefer to use "realistic voting" rather than "optimal voting" for this criterion. [endquote] Above, I told why that would be problematic. You said: However, I believe that you are wrong for both [realistic & optimal] [endquote] One nice thing about u/a elections is that the strategy is a lot simpler to determine. There just can't be any doubt, can there, about the u/a optimality of extreme-rating in MJ? I think that MJ's optimal strategy is the same as that of Score, u/a or not, but I don't have a rigorous proof. MJ's non-u/a strategy might have to remain unresolved, unless someone can supply a proof. In the meantime, its u/a strategy is obvious and uncontroversial. And, if MJ's advocates and its opponents can't prove what MJ's non-u/a, non-0-info strategy is--Doesn't that count against MJ as a proposal for our official public elections if you don't believe that our official elections are u/a? So there are two possibilities: Either MJ's strategy is the same as that of Score, or it's unproven _what_ it is. Either way, are you sure you want to propose MJ? ...We certainly don't have 0-info elections, as I said earlier. > In fact, we have non-0-info u/a elections, Unproven assertion. I believe that for over half the electorate, the information limits are more salient than the U/A aspects. [endquote] Nearly all voters firmly believe that the winner will always be a Democrat or a Republican, and that it can't be otherwise, no matter how they vote (because, in their belief, nearly all the other voters will always vote only for Dem or Repub). There is nothing 0-info about that. Information needn't be valid. False information is still information. There is no lack of definite winnability-information. The virtually universal belief is that only the Democrats and Republican are winnable. No 0-info there. Proof? Ask anyone. You yourself vote Democrat because you think that only the Dem or Repub can win. I don't, but nearly all Dem>Repub voters do, even if Dem isn't their favorite. (Note that earlier I said that absolute rating was the optimal strategy in the 0-info limit, [endquote] That is a class 2 claim--Unlikely, and wouldn't help MJ even if it were true (because our elections aren't 0-info). You said: *and* that it continued to be an optimal strategy with limited information for twice as long as for score or probabilistic approval. I believe that for the majority of voters in the majority of real elections it will still be optimal.) [endquote] A class 3 claim. Unlikely to be true, but would help MJ's value if it were true. (Because if sincere valuation were sufficient strategy, then strategy would be simplified). > Suppose that some set of voters prefer X to Y, and Y to Z. But their > utility difference for X vs Y is very, very small in comparison to > their utility difference for X & Y vs Z. Their optimal strategy in MJ > is to top-rate X and Y, and bottom rate Z. That depends on their expectations for the medians of X, Y, and Z. In particular, if they expect at least two of those medians to be below the second-to-top grade, and the strength of that expectation is greater than the ratio of the expected instrumental utility of voting to the utility of an expressive vote (which is almost certain, because the instrumental utility of voting is infinitesimal)... [enquote] Whoa! When we speak of optimal voting, we're talking about instrumental voting. That's fair, because it's very well established that nearly all voters vote instrumentally. Again, ask anyone. And though your vote, as an individual, isn't important, it's still true that if you belong to a sufficiently large set of voters who believe and voter similarly, then how you and your set vote can and probably does affect the election result. So vote Green. What if everyone more progressive than the SleazeDemocrats voted for what they want? The problem is that you don't think that the others of your preference-set will do other than compromise. Are we all giving it away to a corrupt "compromise" because we're following eachother? You continued: , then they will optimally vote Y at second-to-top. [endquote] See above. Nearly all voters vote instrumentally. You continued: You can even build a quantal-response-type model in which this is instrumentally optimal. [endquote] Build one. > Now Z withdraws. Now there > are only two candidates. Those voters' optimal strategy is now to > top-rate X and bottom rate Y. If that set of voters is large enough, > that could change the winner from Y to X. > That example works at least as well for Approval or Score; in fact, better, because neither objection above (expressivity or quantal-response) applies to either of those. [endquote] I don't deny that Approval and Score fail Strong IIAC. I don't know why Strong IIAC should be passed. I haven't heard any demonstration that MJ will pass it more often. But I agree with you that Strong-IIAC-failure-frequency is a premature topic until we establish what MJ's optimal strategy is. > > Why would MJ fail Strong IIAC less often than would Approval and Score? > > In particular, in our non-0-info u/a elections? > I don't accept this assumption. Obviously I realize that elections are non-0-info, but I believe they are in practice closer to 0-info than they are to u/a for most voters in most elections. [endquote] See above. Ask anyone--Nearly everyone votes instrumentally. As for u/a, that's harder to demonstrate. Because nearly everyone is entirely sure that the winner must always be Dem or Repub, then Repub wouldn't have to be u/a unacceptable in order for thus-believing Green-preferrers to vote Dem. For _me_ the elections are certainly u/a. Maybe, for anyone believing the media, anything other than a Republocrat would be completely unacceptable, just because the tv says so. Mike Ossipoff ---- Election-Methods mailing list - see http://electorama.com/em for list info