Re: [EM] Replies to various people on Condorcet vs RV
Scott Ritchie: So, wait, was half the Condorcet electorate strategic voting by doing order reversal? Are we making the assumption that strategic voting is exactly as common in range and Condorcet in these simulations? That seems a bit strong, exactly because the risks are different and the information required is greater for Condorcet. --WDS: In IEVS, presently, equal rankings are forbidden in rank-order methods. Hence all strategic voting in them involves some order changing whenever the strategic vote is not the honest one. M.O.: which (like Warrens other assumptions) makes the results meaningless. Warren continues: I would not say I am making the assumption that strategic voting is exactly as common in range and Condorcet in these simulations. You are free to make that assumption if you want. I am simply computing the data of what the Bayesian Regrets (and probabilities of electing true-Condorcet-Winners) of different election methods are, at different honesty-strategy mixes in the voter population. At 50-50 mix, range leads to higher CW probability than Condorcet methods. M.O. which is entirely worthless without the assumption that voters are equally sincere in both methods. honest voters (whatever they are - it is rather hard in practice to tell who is who, they all say they are honest if asked; and nothing stops voters from providing votes which include both honesty and strategy inside the same vote) M.O. So use a method that doesnt force dishonesty, a method with which the voter has less need for strategy. then if you provide a good definition of it I may include it in a future version of IEVS. I want to incorporate help and advice from you all. M.O. I offer this help: If Warren wants to make RV look good, then hed be well-advised to not compare it to Condorcet. Continuing to do so will only make RV look really shabby. Wds: I will say, though, that personally I really do not give a damn about how unfair an election method is (and indeed am not even sure what unfairness even is); what I care about is how much society benefits or not, quantitatively, from the election result. If election method A causes expected societal benefit +999 and B causes benefit -999, where benefit is a well defined quantitative thing that we all agree is better to make larger - then I will prefer A even if some whiner comes along and says in his opinion A was more unfair. M.O. Its been long understood on EM that unfairness, such as the need for insincere voting, is very bad news for social utility. You cant expect to get good SU unless people are voting in accordance with their genuine preferences. The familiar lesser-of-2-evils problem causes people to sacrifice sincerity for perceived pragmatism. What is the lesser-of-2-evils problem? It is the fear of fully voting X over Y, because then one cant fully vote Y over Z. Guess what?: RV has the lesser-of-2-evils problem in a transparently obvious way, in a big way that Condorcet doesnt have. Mike Ossipoff election-methods mailing list - see http://electorama.com/em for list info
[EM] Abd reply
Scott Richie: So, wait, was half the Condorcet electorate strategic voting by doing order reversal? Are we making the assumption that strategic voting is exactly as common in range and Condorcet in these simulations? Abd: That would seem to be an unjustified assumption, of course. However, the *only* way to vote strategically in Condorcet is to reverse order. I reply: No, not really. Theres strategic truncation, and theres strategic equal-ranking. But I agree that the only conceivable way to have a strategy _problem_ in wv Condorcet would be if people are doing offensive order-reversal strategy. Scott Richie: . That seems a bit strong, exactly because the risks are different and the information required is greater for Condorcet. Abd: One thing that Warren's work seems to have done is to answer the common objection to Range that sincere voters will be harmed by strategic voters. I reply: No, he hasnt shown that to not be so. Its obvious that it will be so. Abd: That doesn't appear to be true, with a necessary qualification. Harmed must mean Significantly harmed. Further, as I've noted, the meaning of strategic voting is different under Range. It could only refer to magnification. Which isn't order reversal, it's quite a different animal, and, it can easily be argued that it is *not* insincere. I reply: Abd is playing word-games. Define sincere how you want to, but RV will make people afraid to fully vote Favorite over Compromise, because that would prevent them from fully voting Compromise over Worst. Which part of that do some people not understand? In Condorcet wv, you can fully vote both of those pair-wise preferences, and theyll both be fully counted. Mike Ossipoff election-methods mailing list - see http://electorama.com/em for list info
[EM] 2nd Abd reply
Abd says: Range is, essentially, the benchmark. Range was designed to maximize social utility, whereas the other methods were designed to satisfy criteria that were *presumed* to be associated with benefit to society. I reply: Forgive me for presuming that letting people vote sincerely, and electing C.W.s without perfect information, would benefit society. And RV-ists make a big presumption if they believe RV will have enough sincere voting to really maximize SU. The notion that RV will maximize SU, or even do so as well as Condorcet wv, is a fantasy. RV-ists live in La-La Land. Abd continues: Range, in a sense, is designed to satisfy the utility benchmark quite directly. It uses the utility benchmark to choose a winner! I reply: based on the contra-factual assumption that sufficiently many people will vote sincerely. Abd continues: What's interesting here, though, is we now have some measure of *how much* it is better. And under what conditions it is better. How much is Range N, with N2, better than Approval. How much is Range 100 better than Range 10? Of course, I did the same thing with my sims ( http://bolson.org/voting/ sim.html ) way back 4-5 years ago. I designed a simulator that could measure the social utility of election results, and naturally the best result came from the election method which just summed up voter's personal-utility-votes and picked the overall best. That's an awful lot like ideal range voting. And indeed it's great and expressive and better than Condorcet _when everyone is honest_. Right. And this has to be understood. Range is ideal with honest voters. Now, what happens when voters aren't honest? We have a lot of *theory* about this, most of it rather abstracted from any kind of real-world measurement. I reply: That voters will be afraid to sincerely rate Favorite over Compromise, because they feel strategically forced to fully vote Compromise over Worst isnt some abstract theory. Its obvious based on how people vote now. Pluarality isnt RV? Sure but the lesser-of-2-evils need that voters demonstrate now will be there with RV too, and will have predictable results in voting. Abd continues: Simulations are also abstracted, to a degree, but should correlate with real-world performance much better than determining what criteria methods satisfy. A criterion may seem reasonable but may be utterly inapplicable in the real world. I reply: Where does Abd get his assurance about this? He sure doesnt give any justification for it. When its been shown that a method meets a criterion, then its known that there is something that that method will never (or always) do in actual genuine real-world elections. T hats more than you can say for the results of a simulation, especially if its based on ridiculous assumptions, as Warrens simulations are. Abd continues: Do the strategic voters make out unfairly well vs the honest voters? Again, this is another version of the standard objection to Range. If strategic voters under Range reverse preferences, they gain no advantage by it. I reply: A straw-man. Im not aware of RV critics claiming that offensive order-reversal will be a problem in RV. Abd continues: They *may* gain an advantage by voting Approval style, but I would expect that advantage to be small, and, in particular, the harm done to less melodramatic voters is, practically by definition, small. I reply: Abd is barking up the wrong tree. If someone gains advantage by voting Approval style in RV, that isnt a bad thing, in the sense of messing up the result (unless you believe in the fairy-tale of RVs SU maximization). Some people emphasize strategy as something that the method has to combat, in order to not let strategizers wrongfully influence the result. I claim that that is a worthless approach. The genuine strategy problem is when voters are strategically forced to conceal their genuine preferences. Abd continues: I use the pizza election example. A group of people must buy one kind of pizza. They hold an Approval election. A majority prefer Pizza A, in fact, but they also find B acceptable, and they so vote. A minority prefer B and detest A, and they so vote. B, of course, wins under Approval. The B voters gained, the A voters lost (compared to sincere preferences, which, to express, we should really use Range.) But it would not be appropriate to say that the A voters made out unfairly well. They consented. Only if the B voters were being deceptive, they actually had only a small preference for B, but just wanted to get their own way, could we reasonably state that there was some unfair advantage taken. Even then, though, most functional groups would still say, If you want it that much, fine. I'm okay with B, if I wasn't, I wouldn't have approved it. I reply: No one denies that RV would maximize SU under the Fantasy-Land assumption of sincere voting. Mike Ossipoff
[EM] replies to Ossipoff re Range Voting; explanation of latest RV results
WDS: In IEVS, presently, equal rankings are forbidden in rank-order methods. MO: which (like Warren's other assumptions) makes the results meaningless. --WDS: While I agree it would be nice if IEVS did equal rankings, and I plan to make a future version do that, (a) I do not agree I ever made any assumption here. I simply described the status of IEVS. I did not make an assumption. (b) I do not agree every result in the universe that concerns rank order voting methods is meaningless. MO: If Warren wants to make RV look good, then he'd be well-advised to not compare it to Condorcet. Continuing to do so will only make RV look really shabby. --WDS: I resent any implication that my goal with IEVS is to make RV look good. My goal is to investigate data and compare voting methods, as opposed to figuring I have all the answers at the outset. Abd: One thing that Warren's work seems to have done is to answer the common objection to Range that sincere voters will be harmed by strategic voters. MO: No he hasn't... It's obvious that [Smith is wrong]. --WDS: I believe Abd was referring to the following: http://rangevoting.org/StratHonMix.html --WDS: finally, I said I would explain why, in certain parts of the parameter space, IEVS now finds that RV does worse than Condorcet methods. I believe I have a pretty good understanding of that now and you can read it at http://groups.yahoo.com/group/RangeVoting/message/3501 I plan some further experiments which should shed some light on how common this is... Warren D Smith http://rangevoting.org election-methods mailing list - see http://electorama.com/em for list info
[EM] Condorcet and Participation, Moulin's proof
[EM] Condorcet and Participation *Markus Schulze * [EMAIL PROTECTED] mailto:markus.schulze%40alumni.tu-berlin.de /Sun Oct 5 02:48:02 2003/ * Previous message: [EM] lower preferences http://lists.electorama.com/pipermail/election-methods-electorama.com/2003-October/011029.html * Next message: [EM] (no subject) http://lists.electorama.com/pipermail/election-methods-electorama.com/2003-October/011031.html * *Messages sorted by:* [ date ] http://lists.electorama.com/pipermail/election-methods-electorama.com/2003-October/date.html#11030 [ thread ] http://lists.electorama.com/pipermail/election-methods-electorama.com/2003-October/thread.html#11030 [ subject ] http://lists.electorama.com/pipermail/election-methods-electorama.com/2003-October/subject.html#11030 [ author ] http://lists.electorama.com/pipermail/election-methods-electorama.com/2003-October/author.html#11030 Dear participants, this is Moulin's proof that participation and Condorcet are incompatible. Situation 1: 3 ADBC 3 ADCB 4 BCAD 5 DBCA Situation 2: Suppose candidate B is elected with positive probability in situation 1. When we add 6 BDAC voters then candidate B must be elected with positive probability according to participation and candidate D must be elected with certainty according to Condorcet. Situation 3: Suppose candidate C is elected with positive probability in situation 1. When we add 8 CBAD voters then candidate C must be elected with positive probability according to participation and candidate B must be elected with certainty according to Condorcet. Situation 4: Suppose candidate D is elected with positive probability in situation 1. When we add 4 DABC voters then candidate D must be elected with positive probability according to participation and candidate A must be elected with certainty according to Condorcet. Situation 5: Because of the considerations in Situation 2-4 we get to the conclusion that candidate A must be elected with certainty in situation 1. When we add 4 CABD voters then candidate B and candidate D must be elected each with zero probability according to participation. Situation 6: Suppose candidate A is elected with positive probability in situation 5. When we add 6 ACBD voters then candidate A must be elected with positive probability according to participation and candidate C must be elected with certainty according to Condorcet. Situation 7: Suppose candidate C is elected with positive probability in situation 5. When we add 4 CBAD voters then candidate C must be elected with positive probability according to participation and candidate B must be elected with certainty according to Condorcet. Markus Schulze * Previous message: [EM] lower preferences http://lists.electorama.com/pipermail/election-methods-electorama.com/2003-October/011029.html * Next message: [EM] (no subject) http://lists.electorama.com/pipermail/election-methods-electorama.com/2003-October/011031.html * *Messages sorted by:* [ date ] http://lists.electorama.com/pipermail/election-methods-electorama.com/2003-October/date.html#11030 [ thread ] http://lists.electorama.com/pipermail/election-methods-electorama.com/2003-October/thread.html#11030 [ subject ] http://lists.electorama.com/pipermail/election-methods-electorama.com/2003-October/subject.html#11030 [ author ] http://lists.electorama.com/pipermail/election-methods-electorama.com/2003-October/author.html#11030 election-methods mailing list - see http://electorama.com/em for list info
