Re: [EM] Does High Resolution Range offer a solution to the ABE?
2011/11/26 fsimm...@pcc.edu While working with MinMaxCardinalRatingsPairwiseOpposition (MMcrwPO) I got an idea that high resolution Range might have an acceptable solutin to the defection problem that we have been considering: Sincere ballots 49 C x: AB y: BA where x appears to be slightly larger than y in the polls. The A and B factions can agree to enough support such that if they both follow through the one with the larger support will win, but if one defects, C X will win. In this case that level of support is about 96%. If the A voters and the B voters both give 96% to their second choice, then A or B will win, depending on whether or not x is greater than y. If anybody defects from this, then C sill win. This offers an equilibrium which is stable in the sense that if everyone knows everyone else's ballot then nobody has the incentive to defect. But it's drastically unstable and failure-prone if you dont have pre-election polls that measure down to the last ballot. That's one of the main advantages of a system like SODA. Because delegated ballots are assigned after the election, by the time that happens everyone does know the size of each faction down to the last ballot, and so solutions of this nature are in principal feasible. (For instance, this exact solution would work in SODR, that is to say SODA with Range instead of Approval.) Jameson Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] More non-altruistic attacks on IRV usage.
matt welland wrote: On Sat, 2011-11-26 at 22:31 -0500, robert bristow-johnson wrote: On 11/26/11 6:58 PM, matt welland wrote: Also, do folks generally see approval as better than or worse than IRV? they don't know anything about Approval (or Score or Borda or Bucklin or Condorcet) despite some effort by me to illustrate it regarding the state senate race in our county. I wasn't clear. I want to hear opinions from the list: Is approval better or worse than IRV and why? In my opinion, Approval is somewhere between IRV and the advanced methods (good Condorcet methods, MJ, etc). The reason I think Approval is better than IRV is that while IRV makes its own decision about essentially whether to emulate people voting both Nader and Gore, or Nader alone, Approval lets the voters decide on their own. The voters can therefore approve both if it's more important to beat Bush than to support Nader over Gore, or approve Nader only if Nader's got a chance. The reason I think the advanced methods are better than Approval is that they take this burden off the voters when the voters are sincere. If you vote Nader Gore Bush in Schulze (say), then you're both helping Nader to win against (Gore, Bush) and Gore to win against Bush. If Gore is a CW with a sufficient margin that you don't create a cycle - well, then Gore wins. Same with Nader. If there's a cycle, it gets a bit more tricky. The method is easier influenced by strategy and your vote could hurt you. The Condorcet criterion no longer says what the answer should be, and the method thus has to use more indirect reasoning to find out who should win. At least it narrows down the region in which strange things can happen. The good Condorcet methods pass criteria like Smith and independence of Smith-dominated alternatives, and so further narrow down these regions. So, in short: IRV makes a guess as to which comparisons are the most important (using the logic of least first-place votes = worst), and when it gets it wrong, there's your center squeeze. Approval gives the decision to the voters, who will do better if they have access to polling data. Condorcet looks at more comparisons at once, while MJ reads ratings using robust statistics to satisfy criteria like Majority and to deter strategy. Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] More non-altruistic attacks on IRV usage.
2011/11/27 matt welland m...@kiatoa.com On Sat, 2011-11-26 at 22:31 -0500, robert bristow-johnson wrote: On 11/26/11 6:58 PM, matt welland wrote: Also, do folks generally see approval as better than or worse than IRV? they don't know anything about Approval (or Score or Borda or Bucklin or Condorcet) despite some effort by me to illustrate it regarding the state senate race in our county. I wasn't clear. I want to hear opinions from the list: Is approval better or worse than IRV and why? I consider Approval to be better than IRV. Consider the case of Burlington, which I think well-illustrates the flaws of both. Approval could easily have failed in Burlington. Assuming most Republicans bullet voted (which is probably strategically smart), then there would be a chicken dilemma for the Democratic and Progressive voters. They could bullet vote and risk electing the Republican, or approve 2 and give up their voice in the choice between D and P. So in theory any of the three candidates could win. In that sense, Approval is as bad or worse than IRV. But then look at how people would react (if the system were un-repealable). In Approval, people could adjust their vote until they got a result they liked better. The eventual strategic equilibrium would be that the CW would tend to win. In IRV, however, there's no way to change the result without voting dishonestly. So you'd either be stuck with progressives winning, or people would start to use two-party-lesser-evil strategy, and you'd get a two-power lock on power as in plurality. I consider the corrupt, non-competitive nature of either of these long-term results to be far worse than a single spoiled election. Jameson Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Jameson: MTA, MJ, MTAOC, SODA
MIKE OSSIPOFF wrote: If one is going to propose a method involving proxies, then Proxy DD is the biggest and most ambitious improvment. I described it in a posting when you asked about it. Though it's a much more ambitious thing to ask for, maybe people _would_ want a good proxy system such as Proxy DD. A good single-winner method should be used with it. Excuse me for hijacking the thread, but I haven't been following up on the development on proxy direct democracy. I assume this is the same thing as liquid democracy, i.e. that you have a direct democracy where the voters can subscribe or give their voting power to proxies. What's the answer to the vote-buying objection to proxy democracy? This goes something like: we can easily offer some proxy money to vote for X, because we'll simply subscribe to this proxy and see if he tells his constituents to vote for X, and not give him any money if he doesn't. That, if unaddressed, would weaken proxy democracy's counterbalance to the power of money. Election-Methods mailing list - see http://electorama.com/em for list info
[EM] STV and single constraints, like gender quotas
Dear all, do anyone of you know the best way to incorporate single constraints into STV and proportional rankings from STV (see for instance: http://www.votingmatters.org.uk/issue9/p5.htm)? For instance, the constraint can be that at least 1/3 of the elected seats go to candidates of each gender. I found some information in the links below, but I wonder if there are better or more recent suggestions: http://www.votingmatters.org.uk/ISSUE9/P1.HTM http://www.votingmatters.org.uk/issue9/p5.htm Best regards Peter Zborník Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Jameson: MTA, MJ, MTAOC, SODA
2011/11/26 MIKE OSSIPOFF nkk...@hotmail.com Jameson: You said: There are other methods which you don't mention even though their advantages are similar to those of the ones you do. 2011/11/25 MIKE OSSIPOFF nkk...@hotmail.com Regarding the co-operation/defection problem, there are about 4 possibilities: 1. Just propose MTA and Keep the co-operation/defection problem. Majority Judgment has similar advantages to MTA in this case. [endquote] Does it? Who knows? Anyone who takes the time to read the academic literaturehttps://sites.google.com/site/ridalaraki/majority-judgment . Have its proponents told what criteria it meets and specifically what guarantees it offers? How does it do in the Approval bad-example? Same as MTA. That is, honest-votes will reliably give a good result, unlike unstable Approval; but strategic voting will lead to failure. (to compare it to MTAOC) If you're unwilling to research the published answers to your own questions, why do you persist in asking us to look up your alphabet soup in old posts? For instance, I know what you mean by MTAOC (a system with a strong dishonest-fill incentive, which could be almost as bad as Borda in practice), but searching past messages for that acronym just gives the written-out name, and then it would take a separate search (which, if you happened to be using a strict search engine, would fail) to find the actual definition. What majority-rule guarantees does it offer? Does it meet 3P or 1CM? It meets 3P, which I happen to remember what it means. If you define 1CMhttp://wiki.electorama.com/wiki/1CMI'll tell you if it meets that. It probably has a strategy situation very much like that of ordinary RV. The method of summed scores. No. For most voters in real-world studies of MJ, their honest, not-even-normalized MJ ballot was strategically optimal. That is clearly far better than Range. 4. Find a simpler method that has those advantages. Such as SODA. [endquote] Go ahead and propose the enactment of SODA somewhere if you think that a method involving delegates or proxies is as winnable as methods that do not. I am working to do so. Note that SODA proxies are 100% optional, and also bound to a predeclared strategy in ways that should prevent most corrupt proxy use. If one is going to propose a method involving proxies, then Proxy DD is the biggest and most ambitious improvment. I described it in a posting when you asked about it. Yes, you reinvented Liquid Democracy / Asset Voting / Delegable Proxy. That's a very good system but it is a far, far more radical change than SODA. As Kristofer pointed out, for one thing it abandons the secret ballot entirely. Jameson Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] MMPO tiebreakers that don't violate FBC.
fsimm...@pcc.edu wrote: Mike, I like MMPO2 because (unlike MMPO1) it takes into account opposition from supporters of eliminated candidates, so is more broad based, and it is easily seen to satisfy the FBC. Also it allows more brad based support than MMPO3 where only the support by top raters is considered in the tie breaking process. MMPO2 sounds a lot like what I've called Ext-Minmax, but with pairwise opposition instead of wv or margins. I originally devised of Ext-Minmax to resolve some tie problems while checking Smith,Minmax(margins) for mono-add-top failures - I didn't find any, but Kevin Venzke did. What would the pairwise opposition equivalent of the Smith set be? Would it still be the Smith set - and would Smith,Ext-MMPO (to coin a term) pass mono-add-top? Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] STV and single constraints, like gender quotas
Peter Zbornik wrote: Dear all, do anyone of you know the best way to incorporate single constraints into STV and proportional rankings from STV (see for instance: http://www.votingmatters.org.uk/issue9/p5.htm)? For instance, the constraint can be that at least 1/3 of the elected seats go to candidates of each gender. I found some information in the links below, but I wonder if there are better or more recent suggestions: http://www.votingmatters.org.uk/ISSUE9/P1.HTM http://www.votingmatters.org.uk/issue9/p5.htm I don't know of any better rules than the naive rule off the top of my head. I will note this, however: if you use a combinatorial method like Schulze STV, it is very easy to accommodate both simple and complex rules. You just decide to consider only those seat compositions that are permitted by the constraints. For instance, if you need at least one black and at least one woman (but they can be the same person), then you enumerate all possible permutations and remove those that have no blacks and no women. Then you run Schulze STV (or combinatorial method of choice) with respect to what's left. This also works for constraints that can't easily be determined in advance or from the ballots themselves. If you say that the CW based on the same ballots, or the current chairman's pick, has to be on the council, first run the ballots through a Condorcet method (or ask the chairman) and only consider the seat compositions where the candidate in question is included. I suppose you could make ordinary STV combinatorial by considering how many voters did we have to overrule to get the composition we wanted (where this is measured as number of last preferences for the candidate that was eliminated in each round, less the number of last preferences for the candidate that would have been eliminated by ordinary STV rules, using a forced elimination sequence that minimizes this number for the given composition), but it's not clear to me how you would go about actually calculating that minimizing sequence. Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] STV and single constraints, like gender quotas
Hi Kristofer, I don't consider Schulze STV, only standard STV (IRV-based, fractional static Droop quotas, not meek), since it is the only method, which is simple to explain to non-enthusiasts and widely used and have tested and widely used software support for vote counting. I guess, that by the naive approach you mean: elect seats normally, if during the vote-count the, same number of seats remain must belong to one quota group in order not to break the quota (i.e. if. all remaining seats must belong to one quota group), elect only candidates from this quota group. Do you also to the naive approach count guarding candidates from elimination, if it could mean not filling the quotas? I guess a combinatorial method is CPO-STV and Schulze-STV? I consider only single constraints (i.e. no combination of women and skin color etc.). I didn't understand your proposal how you could make ordinary STV combinatorial. Best regards Peter Zborník 2011/11/27 Kristofer Munsterhjelm km_el...@lavabit.com: Peter Zbornik wrote: Dear all, do anyone of you know the best way to incorporate single constraints into STV and proportional rankings from STV (see for instance: http://www.votingmatters.org.uk/issue9/p5.htm)? For instance, the constraint can be that at least 1/3 of the elected seats go to candidates of each gender. I found some information in the links below, but I wonder if there are better or more recent suggestions: http://www.votingmatters.org.uk/ISSUE9/P1.HTM http://www.votingmatters.org.uk/issue9/p5.htm I don't know of any better rules than the naive rule off the top of my head. I will note this, however: if you use a combinatorial method like Schulze STV, it is very easy to accommodate both simple and complex rules. You just decide to consider only those seat compositions that are permitted by the constraints. For instance, if you need at least one black and at least one woman (but they can be the same person), then you enumerate all possible permutations and remove those that have no blacks and no women. Then you run Schulze STV (or combinatorial method of choice) with respect to what's left. This also works for constraints that can't easily be determined in advance or from the ballots themselves. If you say that the CW based on the same ballots, or the current chairman's pick, has to be on the council, first run the ballots through a Condorcet method (or ask the chairman) and only consider the seat compositions where the candidate in question is included. I suppose you could make ordinary STV combinatorial by considering how many voters did we have to overrule to get the composition we wanted (where this is measured as number of last preferences for the candidate that was eliminated in each round, less the number of last preferences for the candidate that would have been eliminated by ordinary STV rules, using a forced elimination sequence that minimizes this number for the given composition), but it's not clear to me how you would go about actually calculating that minimizing sequence. Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] STV and single constraints, like gender quotas
Peter Zbornik wrote: Hi Kristofer, I don't consider Schulze STV, only standard STV (IRV-based, fractional static Droop quotas, not meek), since it is the only method, which is simple to explain to non-enthusiasts and widely used and have tested and widely used software support for vote counting. I guess, that by the naive approach you mean: elect seats normally, if during the vote-count the, same number of seats remain must belong to one quota group in order not to break the quota (i.e. if. all remaining seats must belong to one quota group), elect only candidates from this quota group. Do you also to the naive approach count guarding candidates from elimination, if it could mean not filling the quotas? Yes. These are the Church of England rules mentioned in your first link. If you need max 5 women, and 5 women have been elected, eliminate all remaining men; if you need min 5 women and only 5 women are left, protect them from elimination. I guess a combinatorial method is CPO-STV and Schulze-STV? A combinatorial method is any method that considers all possible ways to assign candidates to seats, and then determines the best assembly according to some rule. CPO-STV and Schulze STV would be combinatorial methods, as would (exhaustive) PAV and birational voting. I consider only single constraints (i.e. no combination of women and skin color etc.). I didn't understand your proposal how you could make ordinary STV combinatorial. Okay, if you only consider single constraints, the Church rules should work. As for making ordinary STV combinatorial, this is just trying to attach a metric to STV. Ordinary STV could be considered to elect the best assembly according to some measure involving the number of last-place votes for the candidates eliminated in each round. If that's the case, it should be possible to force STV to eliminate candidates in a certain order and then measure how good the resulting assembly is in comparison to the best possible. Then you could pick the one that is closest to best while still giving an assembly that passes the constraints. For instance, say that ordinary STV for 2 seats goes like this: A is elected B is eliminated (first pref votes: C: 40, D: 35, B: 30). C is elected all done. This gets a score of 0, because the person with least last place votes was eliminated in the second round. Then say we force D to be eliminated in the second round. Then we'd get: A is elected D is eliminated (fpv: C: 40, D: 35, B: 30). Penalty is 35-30 = 5. B is elected (say). all done. Then this has a penalty of 5 because STV would have eliminated B (at 30 first place votes) but you forced it to eliminate D (at 35) instead. The problem is that, if you increase the number of seats, eliminate D then eliminate B is not the same thing as eliminate B then eliminate D. To be fair, you'd only have to count the order which gives the least penalty, and it's not obvious to me how that would be done. Besides, the method is extremely complex. Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] More non-altruistic attacks on IRV usage.
On 27.11.2011, at 8.05, matt welland wrote: On Sat, 2011-11-26 at 22:31 -0500, robert bristow-johnson wrote: On 11/26/11 6:58 PM, matt welland wrote: Also, do folks generally see approval as better than or worse than IRV? they don't know anything about Approval (or Score or Borda or Bucklin or Condorcet) despite some effort by me to illustrate it regarding the state senate race in our county. I wasn't clear. I want to hear opinions from the list: Is approval better or worse than IRV and why? Unlike others, I think Approval might be worse. Lets assume that there are two wings, left and right. Left has slight majority this time. Left consists of multiple candidates or multiple parties. Right has one candidate. One basic problem of Approval is that all left supporters have to approve all plausible winners of the left wing in order to guarantee that left will win. That makes Approval quite numb to the opinions of the voters. If (almost) all approve all, the choice among left wing candidates will be random. Some voters might be tempted to approve only their favourites, and make them win this way. They may well succeed. But if number of strategic voters grows, then right wins. This kind of close competitions are not rare in politics. And in such situations one can not tell which candidate is the strongest among the left wing candidates (and a natural choice that all left supporters should approve). All candidates present themselves as likely winners, and their supporters tend to think that their favourite candidate is the strongest one. Approval is nice because the ballots are simple. It works fine with two major parties and some new third parties. But when the third parties grow, the problems arise. There are no good solutions and no good guidance to the left voters in the situation where left wing has two or more plausible winners. If one of the left wing candidates is a Condorcet winner (closer to the centre than the competing candidate), then that candidate may propose that all supporters of the other candidate should approve him although his supporters need not approve that other candidate. Maybe there are some voters that would even rank the right candidate second. But often there is no such clear order. And the other left candidate might be slightly ahead in first preferences. IRV has its problems too. The reason why it might be better than Approval is that voters still have some sensible strategies, like ability to compromise. In the environment above left wing IRV voters will anyway rank all left wing candidates first. One of them will win, although the best of them might be eliminated too early. If there are two equally strong left candidates, the number of first preferences will decide which one of the left candidates will win. That is not as bad as the problems of Approval in this situation. In IRV minor parties are a bigger problem than in Approval. In this example they may steal first preference votes from the second favourite of their supporters, and thereby make some worse left wing candidate win. In this situation the voters may compromise. If their own candidate has no chances to win, they might be ok with ranking the stronger second favourite above him. Not good, but at least the voters can do something. And even if they will do nothing, they would still get a left winner. If there is a clear Condorcet winner (like in Burlington), IRV will have problems. So will Approval. But this mail is already too long, so I'll stop here. My basic argument against Approval is that although IRV may make wrong decisions, it does not lead to as terrible situations as Approval does (with more than two plausible winners). In Approval the idea of all left wing voters approving all the left wing candidates sounds quite impossible. Therefore it is likely to violate the opinion of the majority. And the voters do not have any good strategies to fix the problem. Approving all the left wing candidates and letting a random one of them win, or to allow others (maybe the few strategic voters) to decide, does not sound like a system that voters would like to keep. In IRV people are (as we have seen) quite ignorant and don't understand that someone else than the (fair) IRV winner should have won. The results are a bit random, but often people just think better luck next time. So, impossible situations vs. randomish elimination process. Juho Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] More non-altruistic attacks on IRV usage.
David L Wetzell wrote: The two major-party equilibrium would be centered around the de facto center. But positioning yourself around the de facto center is dangerous in IRV. You might get center-squeezed unless either you or your voters start using strategic lesser-evil logic - the same sort of logic that IRV was supposed to free you from by being impervious to spoilers. dlw: the cost of campaigning in less local elections is high enuf that it's hard for a major party to get center-squeezed. And if such did happen, they could reposition to prevent it. Yes, I said that parties or voters could escape this problem by repositioning, i.e. adopting strategic lesser-evil logic. If the cost of campaigning is high enough that only the two major parties can play the game, then money (what you call $peech) will still have serious influence. You might say that this is counterbalanced by the more local elections, so that minor parties can grow into major ones and there will be different minor-to-major parties in each location -- but you still have to convince the more local divisions (counties, cities, etc) to use IRV, and so the same problem applies there. Or in other words: if you're right and there are only two major parties on the national scene (and so no center-squeeze problem), there will still be a center-squeeze problem in, say, Burlington's mayoral elections. Either Burlington has only two major parties (but then where would your more-local accountability come from?) or it has multiple parties, each of which has its own mayoral candidate, and the centermost n of which will be susceptible to center squeeze. You want local areas to support smaller parties so they can grow and challenge the major parties. Well, then the local environment must be conducive to growth. If the parties have to strategically balance IRV's center squeeze (which forces them towards the wings) against the voter support they get from moving closer to the center, that's not exactly conducive to such growth. Nor is it so if the voters have to keep the breakdown point of IRV (when minor becomes major) in mind when voting. Can the parties really be as flexible as you'd like when they're facing the additional constraint of having to walk that tightrope produced by the election method itself? (It might well be that the nature of IRV, plus cost of campaigning means there could only be two national-level parties. I don't think cost of campaigning alone would force there to be only two national-level parties - e.g. France - but the answer to that question isn't critical to what I wrote above. I'm saying that even if we assume what you're saying, you get into trouble on a more local level.) Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] STV and single constraints, like gender quotas
Peter If you haven't already found the Church of England Regulations for STV with constraints, they are here: http://www.churchofengland.org/media/1307318/stv%20regulations.doc These are the only published regulations for STV with constraints that I know of. Your first link (below) is to a Joe Otten paper that describes one way of ordering a list with STV. If that is one of the tasks you have, you may find it useful also to look at the method devised by Colin Rosenstiel: http://www.cix.co.uk/~rosenstiel/stv/orderstv.htm and http://www.cix.co.uk/~rosenstiel/stv/ordstvdt.htm James Gilmour -Original Message- From: election-methods-boun...@lists.electorama.com [mailto:election-methods-boun...@lists.electorama.com] On Behalf Of Peter Zbornik Sent: Sunday, November 27, 2011 10:55 AM To: Election Methods; election-methods Subject: [EM] STV and single constraints, like gender quotas Dear all, do anyone of you know the best way to incorporate single constraints into STV and proportional rankings from STV (see for instance: http://www.votingmatters.org.uk/issue9/p5.htm)? For instance, the constraint can be that at least 1/3 of the elected seats go to candidates of each gender. I found some information in the links below, but I wonder if there are better or more recent suggestions: http://www.votingmatters.org.uk/ISSUE9/P1.HTM http://www.votingmatters.org.uk/issue9/p5.htm Best regards Peter Zborník Election-Methods mailing list - see http://electorama.com/em for list info Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] STV and single constraints, like gender quotas
On 27.11.2011, at 12.55, Peter Zbornik wrote: Dear all, do anyone of you know the best way to incorporate single constraints into STV and proportional rankings from STV (see for instance: http://www.votingmatters.org.uk/issue9/p5.htm)? For instance, the constraint can be that at least 1/3 of the elected seats go to candidates of each gender. I found some information in the links below, but I wonder if there are better or more recent suggestions: http://www.votingmatters.org.uk/ISSUE9/P1.HTM http://www.votingmatters.org.uk/issue9/p5.htm Best regards Peter Zborník I once implemented such a method (brute force and optimizing versions). The implementation was quite straight forward. It just considered results that meet certain criteria better than other results. It included (and started with) proportional raking (planned to elect e.g. chairmen for the group at the same time), and ability to elect certain number of representatives from various (possibly overlapping groups). The implementation fixed the representatives that were elected using proportional ordering (i.e. they were not changed afterwards in the full proportional phase even if there was some more proportional result (resulting iteration could be too complex)). That was thus a quite straight forward exercise, and I didn't have any other interesting options / criteria in my mind to implement. One could support at least, exactly or at most certain number of representatives from a certain set. The proportional ranking based group of chairmen could also have similar requirements. With multiple groups you could say e.g. that there must be at least 3 blacks, at least 3 women and at least 5 representatives that are either black or women. What other rules would be useful? Juho Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Approval vs. IRV
Nov 2011 23:05:49 -0700 From: matt welland m...@kiatoa.com I wasn't clear. I want to hear opinions from the list: Is approval better or worse than IRV and why? Approval is a far superior system to FPTP and IRV because approval: 1. unlike FPTP and IRV, it solves the spoiler problem of a nonwinning candidate altering who would otherwise win; 2. unlike IRV, it is precinct-summable and easy to manually statistically audit for accuracy and so preserves or allows for timely, understandable, election accuracy verification; 3. unlike IRV, it looks at all the candidate choices of all voters, thus treating all voters' votes equally and fairly and is thus monotonic; 4. unlike IRV, it is simple to implement using the same ballot style as FPTP, with a fairly simple programming change in the tally program; 5. unlike IRV, it preserves the rights of voters to have their votes counted fairly and equally with other voters and to participate in the final counting rounds (final decision-making process); 6. unlike IRV, It is very simple for voters to figure out how to best strategize (i.e. for single-winner elections, If your favorite candidate is one of the top-two most likely vote-getters, bullet vote. Otherwise, vote for both your favorite(s) and one of the likely top-two vote getters. In other words, the simple principle is that a vote for your 2nd choice candidate may cause the 2nd choice, rather than your 1st choice candidate to win, so vote for a 2nd, 3rd,... choice if you don't mind them winning the contest.) 7, unlike IRV, it increases the chances of a popular 3rd party candidate winning rather than being a system for keeping the smaller party candidates from interfering with the 2 major parties (true once people figure out how to strategize with IRV by ranking one of the 2 major party candidates 1st) In other words, approval voting is administratively, educationally, and technically simple and equitable, and thus doable - and unlike IRV actually makes substantial improvements over FPTP because it solves the spoiler problem and does not create nonmonotonicity and huge administrative, technical, auditability and other practical problems. -- Kathy Dopp http://electionmathematics.org Town of Colonie, NY 12304 One of the best ways to keep any conversation civil is to support the discussion with true facts. Renewable energy is homeland security. Fundamentals of Verifiable Elections http://kathydopp.com/wordpress/?p=174 View some of my research on my SSRN Author page: http://ssrn.com/author=1451051 Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] More non-altruistic attacks on IRV usage.
David L Wetzell wrote: KM:I think this is where we differ, really. On a scale from 0 to 1, you think their relative merit is something like: 0: Plurality 0.7: IRV3/AV3 0.72: Condorcet, MJ, etc while I think it's something like: 0: Plurality 0.25: IRV 0.3: IRV3/AV3 0.7: Condorcet, MJ, etc. (Rough numbers.) If you're right, of course arguing for Condorcet seems like an angels-on-the-head-of-a-pin thing - and it's even harmful because X_IRV * p(IRV) X_Condorcet * p(Condorcet) . The step from IRV3/AV3 to Condorcet is only 0.02 after all, and the momentum difference is huge! But if I'm right (and this is why I keep bringing up the examples where IRV has been used), then going for IRV is much more likely to rebound on you later. dlw: This is a good statement of our diffs. I'd say I rank the partial use of PR to get a contested duopoly (or to prevent a contested monopoly) very high, while you rank it rather low, especially relative to the development of a multi-party system, not unlike what you have in Norway. This is likely a matter of political cultural differences, which makes my valuations more likely to be prevalent in the US. I base my low confidence of PR's capacity to pull stronger towards competition than IRV does towards consolidation in that IRV pulls stronger wherever it's been tried. You say they aren't applicable. You may have that opinion, but then there's little I can show that will help. So there are two disagreements. Ultimately, I think that multiparty democracy would be better than your contested two-party rule. I could pull market analogies for this (oligopolies and cartels), or I could simply say it's harder to buy off ten than to buy off two. Here you may claim that this is because of my political difference if you want to do so. However, stronger is this: even if you wanted a contested two-party rule, I think IRV would pull too strongly. Again I take my evidence from other countries where that is the case - where the major two are the same as they have been a long time ago, and again, you say that's not applicable. Of course, nothing is absolute: even with Plurality, your own major parties have changed a few times since the time of the Founding Fathers. I just don't think IRV will make a difference. So if we boil down our disagreement further, I think that we *can* generalize from other IRV nations. You think we can't, because your rules are different. There have been many IRV elections (so there are samples to pick), but not very many different systems of government in which IRV is placed. If I pull 100 local Australian elections and NatLibs or Labor win in 95 of them, you could say that's because of the Australian rules so they only count as one sample. I think you're judging IRV too harshly on account of Burlington VT. The sample size is too small to make such a strong judgment. Well, Burlington just confirms things. The simulations say IRV can fail to pick the CW, and may squeeze the center out, and the less minor the minor parties are, the worse it gets. As Burlington agrees with the simulations, that doesn't count in IRV's favor. 4. This is why I pick away at how the args in favor of other election rules get watered down or annihilated when you make the homo politicus / rational choice assumptions more realistic or you reduce the number of effective candidates, or you consider how perceived biases/errors get averaged out over time and space, or you focus on the import of marketing and how IRV has the advantage in that area of critical importance to the probability of successful replacement of FPTP. You try to do so. From my point of view, when I give you examples from the real world, you say that it'll be different here (re Australia on the one hand and France on the other, for instance). When I pull from theory, you say that the theory doesn't apply because it assumes too much; and when I pick examples where theory and practice seem to agree (Burlington), you say that that's just because the status-quo-ists put pressure to bear on IRV. dlw: 1. Well, the sample of IRV uses is small, which makes it hard to render verdict on it. So why would IRV improve things enough over Plurality? That verdict, too, has to come from somewhere. 2. AU does use IRV/PR in the opposite from ideal mix if the goal is to increase the number of competitive elections. 3. WRT France, we disagreed on matters of taxonomy. I classified their top two as a hybrid. You classified it as a winner-take-all and used it to show how IRV has been improved upon and could be improved upon further. Let me try your pragmatism for a minute. You say that our disagreement about top-two is taxonomy. Why should taxonomy matter, though? If I have a tacs-type voting method, and an intar-type voting
Re: [EM] Approval vs. IRV
On 27.11.2011, at 18.35, Kathy Dopp wrote: Nov 2011 23:05:49 -0700 From: matt welland m...@kiatoa.com I wasn't clear. I want to hear opinions from the list: Is approval better or worse than IRV and why? Approval is a far superior system to FPTP and IRV because approval: 1. unlike FPTP and IRV, it solves the spoiler problem of a nonwinning candidate altering who would otherwise win; True. In Approval nonwinning candidates cause no harm. But plausible winners may spoil the election. 2. unlike IRV, it is precinct-summable and easy to manually statistically audit for accuracy and so preserves or allows for timely, understandable, election accuracy verification; True. But it is also possible to record the votes locally in IRV and then send the collected data forward (and based on that data, check the votes later locally). 3. unlike IRV, it looks at all the candidate choices of all voters, thus treating all voters' votes equally and fairly and is thus monotonic; True. But Approval collects only very little information, and in that sense it does not look at many of the preferences of the voters. 4. unlike IRV, it is simple to implement using the same ballot style as FPTP, with a fairly simple programming change in the tally program; In the USA Approval can often be implemented with only small changes to the FPTP procedure. But that is a local and history dependent criterion (i.e. does not apply in some other countries). 5. unlike IRV, it preserves the rights of voters to have their votes counted fairly and equally with other voters and to participate in the final counting rounds (final decision-making process); The algorithm of IRV is quite weird, but fully ranked votes will participate also in the final rounds. Approval has its own problems. If it turns out that candidates A and B were the most popular candidates, voters who approved both of them or neither of them may feel that their vote was not counted when the final decision was made. 6. unlike IRV, It is very simple for voters to figure out how to best strategize (i.e. for single-winner elections, If your favorite candidate is one of the top-two most likely vote-getters, bullet vote. Otherwise, vote for both your favorite(s) and one of the likely top-two vote getters. In other words, the simple principle is that a vote for your 2nd choice candidate may cause the 2nd choice, rather than your 1st choice candidate to win, so vote for a 2nd, 3rd,... choice if you don't mind them winning the contest.) In Approval finding the best strategy may be very difficult when the number of potential winners is three or higher (that is maybe my biggest concern in Approval). Also in IRV one may easily fail to find the best strategy (and the result of the election may get worse). In IRV sincere voting is however a quite reasonable way to vote. In Approval voters need to identify the best strategy to cast an efficient vote. Sometimes they may face a dilemma where they must either not take position in the key question or risk electing a bad candidate. 7, unlike IRV, it increases the chances of a popular 3rd party candidate winning rather than being a system for keeping the smaller party candidates from interfering with the 2 major parties (true once people figure out how to strategize with IRV by ranking one of the 2 major party candidates 1st) It is true that Approval can elect compromise candidates, while IRV clearly favours large parties. I consider methods that can elect compromise candidates to be better general purpose single winner methods. But the choice of method depends here very much on what kind of results the society in question wants to have. In the USA where the tradition is e.g. to elect single winners to form single winner governments, I can understand if some people prefer methods that favour large parties. Also methods that aim at electing only from the strongest groupings have their place in the family of voting methods. (Such methods, that would also eliminate some of the problems of IRV, have been discussed recently on this mailing list.) I'm not sure if IRV was planned this way or if that property is accidental. But that property may well be one reason why the old parties are happier to support IRV than some of the other methods (i.e. to keep competition out, not necessarily to support the philosophy of electing only strong candidates). Approval can handle small 3rd parties very well. In a (former) two-party system the problems of Approval are likely to emerge only when those small 3rd parties grow almost as strong as the smaller one of the two old strong parties. In other words, approval voting is administratively, educationally, and technically simple and equitable, and thus doable - and unlike IRV actually makes substantial improvements over FPTP because it solves the spoiler problem and does not create nonmonotonicity and huge administrative,
Re: [EM] Robert Bristow Johnson wrt Burlington et al.
dlw: The two major-party equilibrium would be centered around the de facto center. KM: But positioning yourself around the de facto center is dangerous in IRV. You might get center-squeezed unless either you or your voters start using strategic lesser-evil logic - the same sort of logic that IRV was supposed to free you from by being impervious to spoilers. dlw: the cost of campaigning in less local elections is high enuf that it's hard for a major party to get center-squeezed. And if such did happen, they could reposition to prevent it. RBJthe counterexample, again, is Burlington Vermont. Dems haven't sat in the mayor's chair for decades. dlw: Not sure this is a relevant counter example. With IRV, the two major parties would become the Progs and the Dems who would be centered around the de facto center of Burlington. -- -- Forwarded message -- From: matt welland m...@kiatoa.com RBF: the counterexample, again, is Burlington Vermont. Dems haven't sat in the mayor's chair for decades. MW: Is this due to a split of the liberal vote by progressives or other liberal blocs? Or is it due to a truly Republican leaning demographic? dlw: More to the point, this is not an arg against IRV since it was only tried for one election in Burlington. MW:Also, do folks generally see approval as better than or worse than IRV? To me Approval seems to solve the spoiler problem without introducing any unstable weirdness and it is much simpler and cheaper to do than IRV. dlw: I would not describe IRV as introducing unstable weirdness. It maintains a two-party dominated system and facilitates that those two major parties tend to position themselves around the de facto (shifting) center. What do you think of the IRV3/AV3 system that treats the up to 3 ranked votes as approval votes to get 3 finalists with IRV used in the final stage? -- Forwarded message -- From: robert bristow-johnson r...@audioimagination.com To: election-methods@lists.electorama.com Date: Sat, 26 Nov 2011 22:31:03 -0500 Subject: Re: [EM] More non-altruistic attacks on IRV usage. On 11/26/11 6:58 PM, matt welland wrote: MW:Is this due to a split of the liberal vote by progressives or other liberal blocs? Or is it due to a truly Republican leaning demographic? RBS:Burlington is, for the U.S., a very very liberal town with a well-educated and activist populace. it's the origin of Ben Jerry's and now these two guys are starting a movement ( http://movetoamend.org/ ) to get a constitutional amendment to reverse the obscene Citizens United ruling of the Supreme Court. the far north end of Burlington (called the New North End, also where i live) is a little more suburban in appearance and here is where the GOP hangs in this town. the mayors have been Progs with an occasional GOP. it is precisely the center squeeze syndrome and IRV didn't solve that problem. and without getting Condorcet adopted, i am not sure how it will be reversed. dlw: If you had given IRV another election, it would have likely solved the problem. You cannot seriously think that one Burlington has driven a stake in the heart of IRV for once and forever. RBS:but the only voting methods folks generally see here are FPTP, FPTP with a delayed runoff, and IRV. and, thanks to FairVote, nearly everyone are ignorant of other methods to tabulate the ranked ballot than the STV method in IRV. dlw: And it was hard work to get people to get IRV..., just think how hard it would be to teach them about 4 very heterogeneous election rules. -- Forwarded message -- From: Jameson Quinn jameson.qu...@gmail.com To: David L Wetzell wetze...@gmail.com Date: Sat, 26 Nov 2011 22:32:53 -0600 Subject: Re: [EM] More non-altruistic attacks on IRV usage. Here's I think the crux of your mistake: We can't say it's just a matter of opinion, cuz it's probably not such, I don't want to get too far into philosophical issues here, but I think that in one sense we can basically take it for granted that it's not such: that, in the proverbial phrase, God does, in fact, know whether p(irv_succeeds_broadly | voting_reform_succeeds_broadly ) is close to 1, close to 0.5, or close to 0. (I say that as shorthand; I'm actually quite convinced God doesn't exist, I'm just saying I believe in objective truth.) dlw: Args about God are for another list-serve... I'd say I'd bet my life that P(irv_succeeds_broadly_among_single-winner_elections | maintain existing voting reform strategy(+ IRV3/AV3 tweak)) P(another_election_rule_replaces_irv_and succeeds_broadly_et al. | existing voting reform strategy is subverted on the basis of electoral analytical args + Burlington, VT case-study) But the fact that the truth is out there, does not imply that it is either desirable or possible for people to stop arguing about it before we have much clearer evidence
Re: [EM] An ABE solution
Mike, De : MIKE OSSIPOFF nkk...@hotmail.com À : election-meth...@electorama.com Envoyé le : Samedi 26 Novembre 2011 13h39 Objet : [EM] An ABE solution This was answered in the first part of the paragraph that you're quoting. What Woodall calls a preferential election rule is by definition a rank method. Kevin Kevin said: By definition an election method doesn't use approval ballots. [endquote] Whose definition? Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Re : An ABE solution
Hi Jameson, My perspective is the following: 1. Most real-world elections will have a sincere CW, although that might not be visible from the ballots. 1a. Those elections without a sincere CW don't really have a wrong answer, so I don't worry as much about the pathologies in that case. 2. Therefore, we can divide FBC-violating strategies into two (overlapping) classes: those which work when there is not a CW among the other voters, which I will call offensive strategies, and which usually work by creating a false cycle; and those which work when there is no CW among the other voters, which I will call defensive. 3. I consider that a method with no offensive FBC violations is good enough. That's why I've used those labels: why would defensive strategies be a problem if offensive ones weren't? Having some problems understanding where you're coming from. A defensive FBC-violating strategy isn't likely going to be provoked by an offensive FBC-violating strategy. I would expect it to be provoked by the truncation of other voters. If you want to say that it's enough for methods to not be suspectible to strategies that would necessitiate defensive compromise from other voters, then I might agree, but that is almost the same thing, in practice, as saying the method should satisfy FBC. Kevin, I suspect that you're probably closer to the truth than I am on this, because you have more experience twiddling the knobs on your simulator. But your brief assertions here don't really give me enough fodder for me to understand why I'm wrong, if I am. Do you agree with me that lack of a sincere CW will be rare? Do you agree with me that some methods have strategic possibilities which are irrelevant as long as there is a sincere CW who is known as such by most voters? Do you agree that some FBC violations fall into that category? Apparently you do not agree that all FBC violations which start from a non-CW scenario fall into that category; and apparently this is because non-FBC-violating truncation strategies could cause the non-CW scenario. If I've read you correctly on this, you may well be right, but I don't follow all the logic. But even if I have and you are, the questions in the preceding paragraph are more important for the big picture. Jameson I suspect I don't understand you more than that I think you are wrong. My best guess as to what you are saying involves trying to interpret the thought behind your rhetorical question (why would defensive strategies be a problem if offensive ones weren't) which seems to me to assume that defensive FBC-violating strategies depend on there being offensive FBC-violating strategies. Let's grant that we only care about the situation that there is a sincere CW. I'm not sure how to answer your other questions in the second paragraph. Maybe I'll understand their importance after another exchange. I would like to understand what you are referring to when you talk about an offensive FBC-violating strategy. You say this strategy usually creates a false cycle. Does this strategy also directly betray one's favorite? Or what do you mean by FBC-violating here? If it does betray the favorite, then you seem to be describing a strategy where some voters bury their favorite in order to create a false cycle (probably by creating a pairwise defeat over that favorite, or something comparable in effect) that achieves something preferable. But if this was creating a cycle then I have to wonder who was the preexisting winner? Surely it would have been the favorite? I hope you see where I am coming from. As far as I can understand, the offensive FBC-violating strategy is a strange idea, so I can hardly see it as the obvious thing to blame for provoking defensive FBC-violating strategies. My impression of what provokes defensive FBC-violating strategies is not based on sims. It's just based on asking the question, if there is a sincere CW but not a voted one, what kind of inaccuracies might exist on the cast votes? It could be many things besides offensive compromise. Kevin Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Robert Bristow Johnson wrt Burlington et al.
dlw: I believe you're serious. Like I said, I'm not that motivated by money(especially for a guy with a PhD in Econ.) It's a byproduct of me being an aspie. So I'd feel bad about taking you up on the 2nd one and the first bet is inadequately framed in my view C'mon. Neither of them is worth more than about $60 in net present value. I can afford that plus the risk. I realize that bet 1 is underspecified, but I don't think your direction for specifying it is good because it relies on a lot of work that would be better spent just promoting reform. I think we could develop an objective metric of support which didn't require so much intervention. Jameson Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Robert Bristow Johnson wrt Burlington et al.
meh, I don't want to take bet number 1. This list-serve is skewed towards smart and politically-interested folks, who equally importantly tend to be arm-chair/list-serve/blog activists. Methinks, we tend to project our attributes too much onto the general voting population as a matter of wishful thinking and a relative lack of experience. We also tend to think of the possibilities a lot more and can get attached to our pet rules. It's relatively easy for a smart person like you to come up with a SODA election rule than it is to rally and lead an organization into promoting it successfully for there are different skills involved. We got the former quite a bit and the latter not so much. This leads to conflict because those who think they ought to be calling the shots about the direction of electoral reform are not making the key decisions. And we value different stuff, which tends to lead to further estrangements. My view of myself is that I'm trying to bridge the two somewhat, by being careful about not idealizing voters. And, I'm playing the conservative, a selective defender of the working orthodoxy of electoral activists. I'm defending their marketing pitch and their right to decide what's important and what's not-so-important. What's telling and what's not-so-telling, like the Burlington VT setback for IRV. So I'll take bet number 2, but not number 1. I think we're too estranged from the realities of electoral activism on this list-serve and have other factors that hinder us from coming to a good working consensus and/or properly appreciating the X*P of IRV. dlw On Sun, Nov 27, 2011 at 6:10 PM, Jameson Quinn jameson.qu...@gmail.comwrote: dlw: I believe you're serious. Like I said, I'm not that motivated by money(especially for a guy with a PhD in Econ.) It's a byproduct of me being an aspie. So I'd feel bad about taking you up on the 2nd one and the first bet is inadequately framed in my view C'mon. Neither of them is worth more than about $60 in net present value. I can afford that plus the risk. I realize that bet 1 is underspecified, but I don't think your direction for specifying it is good because it relies on a lot of work that would be better spent just promoting reform. I think we could develop an objective metric of support which didn't require so much intervention. Jameson Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Re to Kristof M
On Sat, Nov 26, 2011 at 3:20 PM, David L Wetzell wetze...@gmail.com wrote: Here's a bunch of responses dlw: SL may be more proportional than LR Hare, but since I'm advocating for the use of a mix of single-winner and multi-winner election rules, I have no problems with the former being biased towards bigger parties and the latter being biased somewhat towards smaller parties. For there's no need to nail PR if PR itself does not nail what we really want PP, proportionality in power. This is also part of why I prefer small-numbered PR rules (less proportional) that increase the no. of competitive elections and maintain the legislator-constituent relationship. KM:You might be able to get something more easily understood yet retaining some of the compensation part of the first version, by doing something like this: first elect the single winner/s. Then start STV with the single winner/s marked as elected (and thus with vote transfers already done). dlw:The rub here is the desirability of guaranteeing that the Condorcet winner is elected. In more local elections that attract less attention, I put less emph on the usefulness of rankings and thereby the Condorcet winner. KM:So the balancing point depends on how much you value single-winner balance against PR diversity. You could probably do some calculations to find out to what degree increasing the single-winner share lowers the probability of small-party kingmakers getting undue power, but ultimately, you'd have to make a value judgement. dlw: I'm intrigued by the 3:1 ratio approach for a number of reasons, including its simplicity... If a party is really popular, it'd typically get 3 of the seats and a two seat edge over its closest rival. This is half of what is the case if it's just a single-winner. If no party is really popular then the top party gets 2 seats and a one seat advantage, only one-fourth of what would typically happen...The goal being: a meld between the de facto current system in countries like the UK and a EU-style PR system... dlw: 1. While all forms of PR fall short of proportionality in representation, the best predictor of proportionality is the number of contested seats. KM:The Hix-Johnston-MacLean document states that these effects are weak. To quote: Turnout is usually higher at elections in countries with PR than in countries without, It also tends to be even higher in PR systems with smaller multi-member constituencies, and also tends to be higher where citizens can express preferential votes between individual politicians from the same political party rather than simply choosing between pre-ordered party lists. In general, the more choice electors are offered, the greater the likelihood that they will turn out and exercise it. However these effects are not particularly strong, there is some evidence that highly complex electoral systems suppress turnout, and turnout levels may partly reflect influences other than the electoral system, for instance in some countries voting is compulsory. So I don't think you can necessarily draw that conclusion. The apparent competitiveness between seats may be lesser (because of what I mentioned above in that single-member districts are much more win-all/lose-all), but that doesn't mean the real change in voter opinion from term to term is any greater in SMD countries. dlw: I interpret what they're saying is that other factors also come into play that impact the competitiveness of elections. So my conclusion could still beuseful, even if it abstracts from a lot of real-world stuff that also affects voter-turnout. The election rules that best guarantee proportionality tend to reduce voter interest in elections, thereby making PR not the key criteria for choosing an election system. 2. Proportionality in representation does not entail proportionality in power and the latter is desired more than the former. As such, it seems that minority dissenters will need to use extra-political methods (not unlike #OWS) to move the center, regardless of whether PR or another mixed system is used. Proportionality in representation is correlated with proportionality in power. The correlation isn't perfect, as Banzhaf and Shapley-Shubik's measures make apparent, but to leap on that and conclude that proportionality isn't proportional... that's unwarranted. dlw: But it waters down the desirability of nailing PR even further and opens the door to a greater valuation of other conflicting criteria. KM:If anything, when proportional representation disagrees with proportionality in power, the power favors the minority parties. Minor party kingmakers can make themselves costly if they know there won't be any coalition without them. Hence the presence of thresholds in most PR systems: these keep too minor parties from becoming potential kingmakers. Over here, the threshold of 4% keeps most swing parties (as one may call them) out of power.
[EM] ranked pair method that resolves beath path ties.
When beat path produces a tie, this method can produce a single winner unless the tie is genuine. It is the same method I presented earlier except for the addition of the Removing step, which resolves the ties. Candidates are classed in two categories: Winners and Losers. Initially, all candidates are Winners. Every candidate has an associated Set of candidates that includes itself and those candidates that have defeated it. Every candidate initially has a set composed of itself and no other candidates. Winners are those candidates who have no Winners in their set aside from themselves. The pairs are ranked in order. All pairs are ranked in the form AB indicating more voters rank A above B than rank B above A. Pairs with equal votes for A above B and B above A are not ranked. For winning votes ranking, AB is ranked higher than CD if more voters ranked A above B than ranked C above D. If the same number of voters ranked A above B as ranked C above D then AB is ranked higher than CD if more voters ranked D above C than ranked B above A. If the same number of voters ranked A above B as ranked C above D and the same number ranked D above C as ranked B above A then these pairs are equally ranked. Affirm each group of equally ranked pairs in order, from highest to lowest. The count can be ended before all pairs have been affirmed if only one Winner remains. Affirming is composed of three steps: Combining sets, Removing candidates from sets, and Reclassifying candidates. Affirming Step 1: Combining When A B is affirmed, the set for candidate A is added to every set that includes candidate B (not just candidate B’s set). The Combining step is performed for all pairs of the same rank before moving on to the Removing step. Affirming Step 2: Removing Each pair of winning candidates that are in each others' sets are deleted from those sets. Example if C is in D's set and D is in C's set and both C and D are winners, then delete C from D's set and delete D from C's set.). All such pairs of candidates are removed before moving on to the Reclassifying step. The inclusion of this step resolves ties that are not resolved by the beat path method. Affirming Step 3: Reclassifying All Winners that now have Winning candidates other than themselves in their set are reclassified as Losers. Example 7 A B C D 6 C D 5 D B A C A B C D A 0 7 12 7 B 5 0 12 7 C 6 6 0 13 D 11 11 5 0 C D 13,5 AC and BC 12,6 DA and DB 11, 7 AB 7,5 affirm CD A(W): A(W) B(W): B(W) C(W): C(W) D(L):C(W), D(L) D was reclassified as a Loser since C(W) is in its set. affirm AC and B C A(W): A(W) B(W): B(W) C(L): A(W), B(W), C(L) D(L): A(W), B(W), C(L), D(L) C was reclassified as a Loser since A(W) and B(W) are in its set. affirm D A and D B A(W): A(W), B(W)*, C(L), D(L) B(W): A(W)*, B(W), C(L), D(L) C(L): A(W), B(W), C(L), D(L) D(L): A(W), B(W), C(L), D(L) A and B are both winners. A is in B's set and B is in A's set. So A is deleted from B's set and B is deleted from A's set. A(W): A(W), C(L), D(L) B(W): B(W), C(L), D(L) C(L): A(W), B(W), C(L), D(L) D(L): A(W), B(W), C(L), D(L) affirm A B A(W):A(W), C(L), D(L) B(L): A(W), B(L), C(L), D(L) C(L): A(W), B(L), C(L), D(L) D(L): A(W), B(L), C(L), D(L) B was reclassified as a Loser since A(W) is in its set. A wins. With beat path, A and B are tied. Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] ranked pair method that resolves beat path ties.
so this is interesting. it seems to be an extension of Tideman ranked-pairs that considers first the margins and then the opposing votes (or winning votes for the opponent) to break ties. is that essentially it? On 11/27/11 10:21 PM, Ross Hyman wrote: When beat path produces a tie, this method can produce a single winner unless the tie is genuine. It is the same method I presented earlier except for the addition of the Removing step, which resolves the ties. Candidates are classed in two categories: Winners and Losers. Initially, all candidates are Winners. Every candidate has an associated Set of candidates that includes itself and those candidates that have defeated it. Every candidate initially has a set composed of itself and no other candidates. Winners are those candidates who have no Winners in their set aside from themselves. The pairs are ranked in order.All pairs are ranked in the form AB indicating more voters rank A above B than rank B above A. now this is ranked pairs w.r.t. margins. Pairs with equal votes for A above B and B above A are not ranked. not immediately, but is this not what the procedure below is about? For winning votes ranking, AB is ranked higher than CD if more voters ranked A above B than ranked C above If the same number of voters ranked A above B as ranked C above D then AB is ranked higher than CD if more voters ranked D above C than ranked B above A. so maybe i got it wrong, first it's Winning Votes that determines the order of ranking and then Margins is used to break the tie? If the same number of voters ranked A above B as ranked C above D and the same number ranked D above C as ranked B above A then these pairs are equally ranked. because *both* the winning votes is tied and the margins is tied. what else is there? i wonder if it would be better to first rank each pair according to Margins and then, in the case of tie of Margins, Winning Votes are used to break the tie to determine which pair result has priority over the other. for some reason, i like Margins because it is the product of the percent spread (which indicates how decisive a defeat is) times the number of voters participating (which indicates how important the pair election is). that product is a natural measure for how important and decisive a pairwise defeat is. Winning Votes, all by itself, should not be the sole (or primary in the present case) decider. what if there is a lot of voters, but the pair-election is close (say a defeat by 1 vote)? it's not a decisive defeat, but Winning Votes would say it is. i think Margins is more salient than Winning Votes. -- r b-j r...@audioimagination.com Imagination is more important than knowledge. Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] ranked pair method that resolves beath path ties.
Dear Ross Hyman, you wrote (27 Nov 2011): A and B are both winners. A is in B's set and B is in A's set. So A is deleted from B's set and B is deleted from A's set. A(W): A(W), C(L), D(L) B(W): B(W), C(L), D(L) C(L): A(W), B(W), C(L), D(L) D(L): A(W), B(W), C(L), D(L) affirm A B A(W):A(W), C(L), D(L) B(L): A(W), B(L), C(L), D(L) C(L): A(W), B(L), C(L), D(L) D(L): A(W), B(L), C(L), D(L) B was reclassified as a Loser since A(W) is in its set. When I understand your proposal correctly, then you are basically saying that, when contradicting beatpaths have the same strength, then they are cancelling each other out and the next strongest beatpath decides. I believe that your proposal can lead to a violation of monotonicity. Let's say that there is one beatpath from candidate X to candidate Y of strength z and two beatpaths from candidate Y to candidate X of strength z. Then these beatpaths cancel each other out. However, if one of the two beatpaths from candidate Y to candidate X is weakened, then this beatpath decides that candidate Y is ranked ahead of candidate X in the collective ranking. (This is problematic especially when the weakened beatpath was the direct comparison Y vs. X.) By the way: In my paper, I also recommend that the ranked pairs method should be used to resolve situations where the Schulze winner is not unique. However, the precise formulation is important. See section 5 stage 3 of my paper: http://m-schulze.webhop.net/schulze1.pdf Markus Schulze Election-Methods mailing list - see http://electorama.com/em for list info
