[EM] (5) MJ -- The easiest method to 'tolerate'
stevebosworth at hotmail.com
Sun Sep 11 16:44:26 PDT 2016
Re: [EM] (5) MJ -- The easiest method to 'tolerate'
From: Kevin Venzke <stepjak at yahoo.fr>
Sent: Thursday, September 8, 2016 8:13 AM
To: steve bosworth; stevebosworth at hotmail.com
Subject: Re: [EM] (4) MJ -- The easiest method to 'tolerate'
Hi Kevin and everyone,
K: Let me be clear that if you are completely sold on MJ, I'm not interested in trying to change your mind. In particular I'm not going to refute Jameson posts solely because they are pro-MJ. That might make sense in a debate with fixed positions, but my assumption is that this isn't a debate, only a discussion.
S: I’m not sure what your distinction is between a ‘debate’ and a ‘discussion’. In any case, I am genuinely searching for the best method for electing a president and in hoping to become better informed as a result of our discussions. Given certain clarifications and your arguments, I am open to the possibility of being shifted from seeing MJ as the best.
K: Major points in this exchange:
1. You clarified the scope of the "half as manipulable" claim, and I can largely stop responding to those references.
S: Does this mean that you accept B&L’s claim in this regard as valid?
K: 2. You seem to be backing away from IIA/Arrow-related claims, so I will drop that issue too.
S: In contrast to all the summing and averaging methods, I do accept that only about half of their IIA problems remain with MJ in the (possibly) rare cases when a voter dishonestly uses MJ’s ballot to rank rather than grade the candidates.
K: 3. I clarify my points regarding the point of an election in general vs. from the perspective of a voter.
S: Do you mean by this that while you have not said what the aim of an election should be, you believe that you have accurately described the attitude that most citizens have when using any of the available methods: they only wish to maximize the chances of their favorite candidate will win?
> S: [….] By ‘manipulation’, B&L and I mean the gaining of an electoral advantage over other voters by a voter who ranks or grades at least one candidate ‘dishonestly’, i.e. a vote that is not a straight forward expression of that voter’s own degree of preference or honest evaluation of that candidate. However, correct me if I am mistaken but some of your later phrases suggest to me that you would actually answer NO, to each of the follow questions:
> 1. Do you agree that the ‘object of … an election is to select … some candidate who shall, in the opinion of a majority of the electors, be most fit for the post….(B&L, Majority Judgment, p.209)? For example, you say: 1): ‘If I could disagree with only one thing, it would be this notion that voters care about discovering the best winner, as opposed to trying to get their preferred candidates elected’; 2): ‘ … I don't see it as an inherently valuable feature of a method for voters to be able to "clearly express his or her evaluation" of a candidate ….’. [If you answer is NO, please try to explain what you think the main ‘object’ of an election should be.]
K: I would answer close to "yes" but I probably would not word it exactly as page 209 does.
S: Please try to put it in your own words.
K: You are missing most of the meaning in the quotes of mine that you included.
S: Sorry, I quoted them because I was not sure of your meaning.
K: The point of an election is not the same thing as what any individual voter [might be] trying to do in that election.
S: I agree.
K: And when I say it's not "inherently valuable" etc. etc. I am just saying the same thing I have said 100 times, that it's not enough to permit it, you should give the voter a self-interested reason to do it.
S: Should not a rational ‘self-interested’ citizen be sufficiently humble to accept that the majority might usually know better than any one voter deciding by himself? Is ‘self-interest’ for you always in conflict with altruism?
K: I certainly don't say it is NOT valuable to be able to clearly express evaluations. It could be.
S: Other things being equal, is it not always better? Under what conditions might you think it would not be valuable?
S: > 2. Do you agree that ‘majorities of grades are … considerably more discerning decisions than are majorities of > preferences’ (p.283)? For example, you say, 1): ‘my criticism is not that MJ is bad, it's that it is needlessly complicated’; 2): ‘MAM is harder to understand, but I think it gets more mileage out of its complexity than MJ gets out of
> its’ [Is this ‘more mileage’ more honest evaluation or something else?],
K: They COULD be more discerning, but whether they practically speaking ARE more discerning would depend on the incentives of the method.
S: Do you agree that, other things being equal, grades are more ‘discerning’ (i.e. informative with regard to the voter’s values) than ranking? Do you know of any method that would allow voters to evaluate candidates more completely and efficiently than does MJ?
K: "More mileage" regarding MAM means if you try to reduce complexity of MAM you would also hurt its performance. Remember that I feel that MJ is too complicated for what it does.
S: I see that MAM has ‘more mileage’ than Approval (as you say), but in what way does it have more than MJ? For example, if an MAM voter ranks A>B>C, this does not allow her to express, e.g. whether this means A is Excellent, B is Very Good (or Good, or Acceptable, or Poor), and C is Good (or Acceptable, or Poor, or Rejected), or A is Acceptable, B is Poor, and C is Rejected, etc.
S: > 3. Do you agree that the ideal voting ‘method should elicit the honest expression of voters’ opinions as inputs, for the aim of an election is to produce … the true wishes of societies ….’ (p.352) For example, you say, 1): ‘I do not care about "preferences" vs "evaluations"’; 2): ‘… a method should elicit the honest expression of opinions as inputs, but I believe they should do that by making it in the voter's strategic interest to express them’; 3): ‘… sincere voters …
>interested in maximizing the effect … should only use the two extreme ratings’; 4):’… the strategic voter can do better than …. simply to grade the candidates ‘honestly’ [Do you want a method that maximizes the chances that a society will discover the winner closest to being excellent, or one that especially helps the most savvy voters manipulatively to get their way?].
K: Quote #2 of mine is the one you should use to answer this question. It is also the answer to the question you ask in square brackets. The method should maximize the odds of finding the best winner by reducing the difference between a sincere and strategic vote. In principle I think we might actually agree on that.
S: Yes we seem to agree on this but do you see any method that more efficiently finds ‘the best winner by reducing the difference between a sincere and strategic vote’ than does MJ? You seem to believe that MJ does not ‘making it in the voter's strategic interest to express … honest … opinions’. Please try to explain this again if you think you have already done so.
>> S: Depending on their own scale of values, I accept that some voter may validly choose to use only these two ‘extreme ratings’. You will see that I agree with you regarding the special case you outline later. However, this is a long way from showing that all voters should ‘usually’ see ‘that only the two extreme ratings can maximize the effect of their vote’.
This is partly because MJ also invites all the other voters who may have a greater knowledge of the many different qualities of the candidates, appropriately from their point of view, to use all 6 grades accurately to evaluate each candidate. Many of them may correctly see that the most efficient way they can help to prevent any of the candidates they evaluate as Poor or want to Reject from winning, is honestly to grade the rest of the candidates from EXCELLENT to ACCEPTABLE. For example, in a French Presidential election where between 10 and 20 candidates may be running, many voters may see at least 2 to 6 candidates that would be at least acceptable and that their honest evaluations of these will help at least one of them to be elected rather than any of the other candidate they evaluate as Poor or to Reject. Such honest voting would both maximize the chance that one of these candidates will win and will best help the process to discover the socially most valued candidate for the office.
K: That's not the issue. Suppose that a voter votes for A and detests B and the winner of that election is B. Does the voter think "the wrong candidate won" or does he think "I was evidently mistaken to think A was best"?
S: Probably not but as a citizen believing in democracy, he might accept that the majority is more likely to be wise that any one citizen deciding on his own.
> S: In any case, whether a voter rationally or irrationally tries to manipulate their MJ ballot, B&L argue that MJ’s structure cuts the probabilities of being successful in this regard by almost ‘half’ (Belinski & Laraki, Majority Judgment, pp.14, 15, 189-198, 212, 245, 282-292)? [….]
> K: Is this quote the basis of the claims that MJ reduces manipulability? Because most methods don't even have the mechanism discussed...
S: Which ‘mechanism’ do you have in mind? Is MJ’s winner winning only by having the highest majority-grade?
K: Like I've said, I understand this claim as a comparison to Range, but not much else.
S: No, instead of ‘point-summing’ I should have said that B&L include all the ‘traditional methods’ in this ‘comparisons’ with MJ.
> K: Yes, that is MJ's intention, and if people do that (rate in comparison to a hypothetical candidate that might not be in the race), then it does not run afoul of Arrow/IIA. However, if voters do the strategically obvious thing of rating their favorite candidate EXCELLENT even if he is not exactly excellent, then in effect the method will not be independent of irrelevant alternatives, and the method isn't dodging Arrow in any meaningful way.
> S: I see B&L as accepting this but still arguing that this use of MJ ballot is still almost half as like to ‘run afoul of Arrow/IIA’. Do you have a reason to disagree with this claim?
K: Well, if neither you nor B&L are defending the idea that MJ dodges all Arrow issues, then that solves that topic entirely as far as I'm concerned. I am not going to quibble about what methods have "more" IIA issues.
S: If MJ is less vulnerable to IIA than all other methods, would not this make us prefer MJ to all the methods that are more vulnerable, i.e. other things being equal? In fact, as I understand it, B&L explains how MJ does at least pass a weaker IIA test, and this is also confirmed by Jameson in his 2 recent informative posts: 1): ‘there is the failure of the later-no-harm (LNH) criterion. But note: MJ actually does pass a weaker version of LNH: rating additional candidates at above bottom will not harm the winner as long as those candidates are ranked below the winning median. My claim is that over time, the winning median grade will mostly fall in a given band of grades; for instance, using letter grades, between B- and D+. In that case, making distinctions between A and B at the top or D and F at the bottom are strategically safe.’ 2): ‘Note that this strategy will almost certainly not affect the medians, and thus will not change the winner. Though technically it breaks IIA, it only does so in bizarre cases where both voter and candidate distributions differ severely from historical norms.’
> K: I think I've probably done simulations on the exact question, I should probably check or make a new one...
> S: Look forward to the results of your ‘new simulation’ which I assume will take account of B&L’s ‘half as likely’ claim.
K: All I intend to find is under what circumstances the strategic voter is better off exaggerating under MJ. I don't really care how small the advantage is, or even know how I would quantify that. Just whether there is an advantage.
> K: I might but probably wouldn't deem it best. I've already explained why I prefer it to MJ: MJ "allows" and "invites" voters to fill out the ballot in a way that is probably not strategically ideal. That feels deceptive to me, in that less savvy voters could be at a disadvantage.
S: For you, what does it mean to be ‘strategically ideal’? Do you have a method in mind that offers it?
> S: I have agreed that MJ can allow something like half as much of the manipulation that might be attempt to be successful as contrasted with other methods. I do not yet see that you have made the case that it does not encourage or at least allow voters ideally (from their own points of view, to attempt dishonestly) to vote strategically. If you can, I would be very interested if you could counter B&L’s claim that MJ is structured in practice to lead most votes to adopt ‘honesty’ as their ‘dominant strategy’.
K: Simulations would have that goal I think.
K: Whether some people use many of the grades isn't the question here, is it? The question is whether the strategic voter is wrong to think he should exaggerate his grades.
S: He is ‘wrong’ if and when by doing so he is not minimizing the chances that one of the candidates he honestly evaluates as Rejected will win. For example, he might do this by grading his 1st choice candidate as Excellent but also Rejects all the other candidates he honestly values as either Excellent, Very Good, Good, or Acceptable.
>> S: Yes, MJ offers ‘different rating [grading] options’, and much less scope for manipulation. Admittedly, the counting of MJ is slightly more complicated than simply summing approvals or scores. However, is not MJ’s potential for periodically and more precisely informing all citizens and candidates about the actual intensities with which the many different scales of values and concerns that actually exist within one’s society an additional benefit well worth this slight additional complication, e.g. a complication which is also much less than any Condorcet methods or IRV?
> K: But it would only do that (i.e. "more precisely informing all citizens and candidates about the actual intensities.....") [only] if voters use it as intended. I don't think they would. If you want to say that Approval isn't going to produce a lot of information on the preferences, I will totally agree, and agree that it's not ideal, but I don't think the conclusion to draw is that MJ is better than Approval.
> S: Please explain why not.
K: It should be clear. If MJ doesn't offer the right incentives to entice people to state actual intensities then (in the extreme case) it isn't actually better than Approval. …
S: Correctly you say, ‘If’. Do you have any method in mind that offers any greater incentive for each voter to evaluate each candidate than that offered by MJ?
S: B&L and I assume that, as believers in democracy, most voters want the winner to be the candidate most highly valued by a majority of all the voters.
> K: I think this is bizarre and unrealistic. It's hard for me to believe that somebody thinks this is what motivates voters. The premise would render moot all concerns, not just about LNHarm, but about probably *all* strategy criteria and guarantees. This is such an unbridgeable gap that I guess we may soon be able to wrap up this discussion.
> S: By saying this, you seem to have not yet taken into account either of B&L’ analyses of their Orsay and other experiments in which most voters used many of the available grades, or Jameson’s recent EM post that argued that the chances of successfully manipulating MJ would be something like 2.5%. If so, would not most people see that the best strategy is usually to simply grade the candidates honestly?
> K: When it comes to expressiveness, I think that practically speaking MAM is actually better than MJ, due to the scenario that MJ turns into Approval and consequently expresses very little.
> S: Please explain how MAM is more ‘expressive’ (or ‘discerning’) than MJ. Also, it seems to me that almost any method could be impoverished by some voters so they would be making only Approval votes, including MAM. It seems to me that MJ is least likely to be impoverished in this way by many voters.
K: MAM has a disincentive against degrading into Approval because it counts relative preferences that the strategic-minded voter would want to use.
S: Yes, and why do you not see MJ as containing this same ‘disincentive against degrading into Approval’, and perhaps even to a greater degree?
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