[quote] Exactly what kind of criteria you would use would depend on the voter population. [endquote]
Quite. Regarding that matter, I'll define two terms here: "Current conditions" means: The conditions existing now, with 1) Media that rarely if ever mention non-Republocrat political parties, platforms, policy-proposals or candidates, and which continually promote the belief that the winner will always be a Democrat or a Republican. ...and the belief that Republocrat corruption, the boughtness of candidates, is a fact of political life and is therefore acceptable because it's inevitable; and 2) An electorate that believes those media claims. "Green scenario" means: Conditions that would exist after our electorate has, via Plurality, elected Green Party candidates to the presidency and most of Congress and state legislatures. As I've mentioned before, any electorate that could do that would be one that doesn't believe the old media disinformation. Additionally, according to the GPUS platform, a Green government would mandate a vastly more open and honest media system, without corporate control, and with the opportunity of extensive public participation and freedom of expression for all, including a much wider range of political parties, candidates and policy positions. In those ways, the Green scenario would be very different from current conditions. The choice of a voting system, the desirability-comparison of voting systems, depends almost entirely on the conditions, such as those conditions described above. [quote] If the voters are very strategic [endquote] ...as they are, under current conditions. Of course one could always speculate that maybe they'd be sincere with a different method. I've discussed that i, in the case of traditional unimproved Condorcet (TUC). [quote] , strategic resistance criteria is [He meant "are"] important or you get garbage-in garbage-out. [endquote] Exactly. Except the use of the word "resistance" reveals confusion about strategy. It implies that strategy is something of an offensive nature that voters might attempt, in order to subvert the voting system results, and that therefore the method needs to be able to resist those nefarious attempts by voters. Wrong. The significant and meaningful strategy problems consist of strategy-needs. The more drastic and preference-distorting the strategy, the worse the strategy-need is. Sure, methods that fail the Chicken Dilemma Criterion (CD) are vulnerable to an offensive defection strategy. But the importance of that comes from the strategy problem that that vulnerability puts on the preferrers of a candidate who is likely to be defected-against. Thus, vulnerability to offensive strategy can cause strategy need/dilemma for other voters, and _that_ is the reason why vulnerability to offensive strategy matters. But the actual strategy problem is the strategy need or strategy dilemma, which may or may not be a result of offensive strategy vulnerability. [quote] If they are not, then accurate translation criteria are more important [endquote] In the Green scenario, FBC isn't nearly as important as it is under current conditions. . But CD still matters, because CD failure can take away most of the meaning and value of Mutual Majority Criterion (MMC). For instance, it does so in the case of Beatpath or Bucklin. Approval has "accurate translation" under all conditions. Even under current conditions, Approval will accurately measure likedness, trustedness and acceptability, and will elect the candidate who liked or trusted by, or acceptable to, the most people. Approval, unlike any Condorcet method, meets Consistency, and all of the monotonicity criteria, including Mono-Raise, Participation, Mono-Add-Top, and Mono-Add-Unique-Top. These must be regarded as "translation criteria". Condorcet methods (all of the that I'm aware of) fail all of the above-listed criteria except for Mono-Raise. Instant Runoff fails Mono-Raise, but doesn't fail Mono-Add-Unique-Top, though Condorcet fails that criterion. Traditional Unimproved Condorcet (TUC), under current conditions, does poorly by "accurate translation", due to its preference-distorting strategy needs. Under Green scenario conditions, TUC isn't as bad, because, as I said, its FBC failure won't matter as much. But its CD failure will still matter, and would reduce TUC's value there too, by compromising any MMC compliance that a TUC method has--as is the case with Beatpath. Symmetrical ICT, under current conditions, at least doesn't have favorite-burial need, or a chicken dilemma. But, under current conditions, Symmetrical ICT will still give strategic incentive to top-rank all of the acceptable candidates (TUC's strategy in that regard isn't even known, and would have to be guessed at by voters). So Symmetrical ICT isn't claimed to encourage completely sincere rankings. Under Green scenario conditions, due to that method's MMC failure, there would still be incentive to top-rate all the acceptable candidates, even within a mutual majority. Under current Conditions, IRV's FBC failure, a particularly flagrant one, quite disqualifies IRV. Under Green scenario conditions, if people want strategy-freeness, an easy, strategy-free choice among their preferred set of candidates, IRV is the very best there is. But I hasten to advise that, if you aren't sure that you'll be in a mutual majority, then you definitely should oppose IRV. Speaking for myself, I _don't_ need easy, strategy-free choice among the set of candidates that I prefer, who, I expect, would likely be a mutual-majority-preferred set. In Approval, I'd approve all of them, and wouldn't consider there to be a need to choose among them. Therefore, I'd prefer Approval to IRV, unless I were sure that the progressives would be a mutual majority that is voted as such. I've written to advise the Greens regarding the considerations for judging the desirability of IRV. That's what my "opposition" to IRV consists of. (Above, I said that you should oppose IRV if you aren't sure that you'll be in a voted mutual majority.) IRV's big advantages result from meeting the following criteria: 1. Mutual Majority Criterion (MMC) 2. Later-No-Harm (LNHa) 3. Clone-Independence 4. Later-No-Help (LNHe) The first two of those criteria are particularly powerful in combination. They ensure that there'd be no need for other than sincere ranking, in a mutual majority. Therefore, the winner would come from that mutual majority's preferred-set. IRV's freedom to rank sincerely, for people in a mutual majority, is unmatched. Well, I shouldn't say that no other method achieves that--it's just that I'm not aware of one. IRV's disadvantages: Though IRV strongly rewards and favors cohesiveness and mutuality, IRV achieves that by strongly penalizing and disfavoring un-cohesiveness and non-mutuality. The freedom from strategy need, for a mutual majority, is achieved by dumping favorite-burial need on those not in a mutual majority. That's due to IRV's FBC failure, and its flagrant Condorcet Criterion failure. That's a good reason to oppose IRV if you might not be in a voted mutual majority. But how wrong, unfair or undemocratic is it? A group that has a majority against it can't expect to win in any method. Then maybe it isn't too unfair if non-mutual-majority voters also don't have the same strategy advantages. Isn't a majority who like eachother's candidates the most important kind? There's nothing wrong or unfair about government by a cohesive majority. Objectively, it sounds fine. As an individual or a faction, whether you should support or oppose it depends on being sure you're in that cohesive majority. But, then, wouldn't most people expect that they'd be in a mutual majority? [quote] the best indicator is actual evidence taken from voters actually ranking or rating candidates [endquote] ...But not meaningfully from organizational elections, where the situation is nothing like official public political elections. [quote] -- and possibly from counterfactual reasoning of the form "if there was a lot of strategy going on here, then results would be like X, but we know results are Y, so there wasn't". [endquote] American voters are explicit about that. They engage in strategic favorite-burial, as their media advise them to. As I said, given their expressed beliefs and assumptions, favorite burial is their optimal strategy in Beatpath, Ranked-Pairs, etc. [quote] I think that the evidence shows there's not an undue amount of strategy by the voters [endquote] How regrettable that Kristofer forgot to specify the evidence :-) American voters make it quite clear that they use favorite-burial strategy, as their media advise them to do (as I said above). And, as I also said above, given their expressed beliefs and assumptions, favorite burial would likewise be the optimal strategy in Beatpath, Ranked-Pairs, Kemeny, etc. I've told why, many times. I discussed it in a recent posting, probably in the "Acronym use" thread. [quote] , while there may be a greater amount of strategy by (comparatively more organized) parties. Thus I think that the method should deter party strategy and be accurate with respect to voters' wishes. [endquote] Accuracy with respect to voters' wishes requires a voting system that doesn't give them strategy needs that will drastically distort their preferences. That disqualifies Beatpath, Ranked-Pairs, etc. Symmetrical ICT would do much better, under current conditions, which is what it's intended for...if a Condorcet method could be enactable :-) As mentioned above, Approval, by counting likedness and acceptability, accurately gives what voters collectively most want, like or find acceptable. But, if it's sincere rankings you want, then you want IRV in the Green scenario. IRV doesn't must meet MMC. Due to compliance with LNHa, and therefore CD, it also allows sincere rankings among a mutual majority. That can't be said of Beatpath or Ranked-Pairs. [quote] - Majority criterion: a majority's wishes on which candidate is elected is respected [endquote] That's vague. Is Kristofer referring to voted majority or preference majority? Voted Majority Criterion: If a majority of the voters vote X over everyone else, then X should win. [end of Voted Majority Criterion] Preference Majority Criterion: If a majority of the voters prefer X to everyone else, and vote sincerely, then X should win. [eend of preference majority criterion definition]] Voted Majority is obviously a special case of MMC. [quote] - Mutual majority criterion: a majority's wishes on which set of candidates the winner comes from is respected [endquote] Likewise vague: MMC: If a certain majority of the voters all prefer a certain same set of candidates, S, to all of the other candidates, then the winner should come from S. [end of MMC definition] [quote] - Condorcet criterion: if there's a candidate that would win a runoff against every other candidate, ballots unchanged, then that candidate should win [endquote] I won't keep commenting on inadequate definitions. But I'll point out that Beatpath's Condorcet Criterion compliance, under current conditions, is made meaningless by its failure of FBC, for the reasons that I discussed in more detail in the "Acronym use' thread, and in many previous postings. Likewise, Beatpath's MMC compliance is compromised by its CD failure, under current conditions, and in the Green scenario too. Evidently, not everyone understands that a method's compliance with one criterion can be made meaningless by its failure of another criterion. [quote] - Smith criterion: if there's a small set of candidates, any of which would win a runoff against any candidate outside the set, with ballots unchanged, then the winner should come from that set. [endquote] Again, terrible definition. But what makes Smith compelling & necessary? Anyone can list a bunch of criteria. It would be quite another thing to actually tell _why_ that person thinks that their listed criteria are important. [quote] - Independence of clones criterion: turning a candidate or party into a bunch of identical candidates or parties (that all voters rank next to each other) shouldn't alter the outcome. [endquote] Desirable, but not necessary, for reasons that I've given here, and at Democracy Chronicles. Beatpath passes, IRV passes, Symmetrical ICT fails. But,, as I described then, failure only results in an Approval-like strategy situation. And Approval strategy is the best that can be achieved by rank methods anyway, under current conditions, especially in a u/a election. As is often pointed out, different people advocate different criteria. At EM, of course we've always heard that going on. What's missing is justifications for that advocacy. I've told why FBC and CD are important. I've told the big advantage of the combination of MMC and LNHa, under Green scenario conditions. Michael Ossipoff ---- Election-Methods mailing list - see http://electorama.com/em for list info