Re: [EM] strategy-free Condorcet method after all!
robert bristow-johnson wrote: robert bristow-johnson wrote: ... i dunno how to, other than take the raw ballot data of some existing IRV elections, but i would like to see how many of these municipal IRV elections, that if the ballots were tabulated according to Condorcet rules, that a cycle would occur. Kristofer Munsterhjelm wrote: ... I haven't run the data through my simulator yet, but it seems cycles are rare. i have to confess that i am less worked up about what pathologies would result from a Condorcet cycle than i am about what pathologies result from FPTP or IRV (or Borda or whoever) failing to elect the Condorcet winner whether such exists. we know the latter actually happens in governmental elections. i still have my doubts to any significant prevalence of the former. That's what the data might provide information about. If it is representative and cycles are rare, then there's little to worry about, except how opponents might exaggerate the faults. If cycles are common, then one should be careful to pick the right cycle-breaker. on the rare occasion a cycle ever happens, probably Tideman Ranked-Pairs would be the best compromise between a fairer Schulze beatpath and some method that has sufficient "lucidity" that voters can understand it and have confidence that no "funny business" is going on. Yes. I think so, too, but Schulze has momentum (within technical organizations, mostly), so the question is which is greater an advantage. but whether it's beatpath or ranked-pairs or IRV rules as the method that resolves a cycle, at least in this very rare occasion, it's picking a non-Condorcet winner meaningfully, even if there are conceptual ways to turn tactical with it. but then, how profitable is it to vote tactically when there is little probability to the conditions that would serve such tactical voting? There would be two kinds, I think: attempted "vote management" by parties and what we might call "ignorant strategy" that the voters do by themselves, and which only distorts the outcome if lots of people do it. The latter is not much of a threat, I think, and the method only has to weather the former for a few elections before the parties see it isn't going to work. In small committees, the two would converge: poison pill type tricks are possible with Condorcet methods, as well, but that's not the application we're speaking of at the moment. if it were one of those Condorcet methods and if there is little likelihood of a cycle happening and if a savvy voter knows that, how does it benefit his/her political interests to do anything other than vote for their fav as their first choice and cover their ass with a tolerable 2nd choice? how are they ever (assuming no cycle) hurting their favorite or helping any unranked candidates (tied for last place, in this voter's esteem) beat the 2nd choice? i really find it hard to see the tactical interests as differing from the sincere political interests. Ignorant strategy could take the form of "I really really hate [major party X], so I'll put him last", where there are also worse candidates in the running, but the voter is used to two-party systems. Burial by accident, as it were. Warren claims that will destroy most Condorcet methods, because DH3 applies to that instance as well, but I'm not so sure. It *does* destroy Borda, but so does agenda manipulating (fielding loads of clones). Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] strategy-free Condorcet method after all!
FPTP: For most elections this can handle the decision needed - though get near a tie and suspicion pushes toward doing a runoff. IRV: Does let voters do ranked voting, but we find plenty of reasons to complain about how it counts the votes. Condorcet: Lets voters do ranked voting for more than one, indicating which they like best. Matters often to let them express their desires more completely when they wish - though they can often adequately express their desires via bullet voting. Matters MUCH, though rarely, to sort out more complex decisions. It is for this ability that we need such as Condorcet. It is for the last topic, where there may be a cycle and no CW, that analyzing votes is more of a challenge. The Llull method will find the CW if it exists. Else it will find a cycle member. Deciding which takes a bit more looking at the N*N array. We debate how to choose a winner, which I claim should only consider cycle members (any cycle member would become CW if other members were rejected). Tactical voting? PROVIDED you know how all others will vote, you may be able to influence results by responding based on what you know. That results can be affected via such makes sense. That you can both have the needed information and modify your vote as you plan is a suspect dream - perhaps someone can do useful analysis as to frequency of attainable useful results for such. Dave Ketchum On Nov 23, 2009, at 5:00 PM, robert bristow-johnson wrote: robert bristow-johnson wrote: ... i dunno how to, other than take the raw ballot data of some existing IRV elections, but i would like to see how many of these municipal IRV elections, that if the ballots were tabulated according to Condorcet rules, that a cycle would occur. Kristofer Munsterhjelm wrote: ... I haven't run the data through my simulator yet, but it seems cycles are rare. i have to confess that i am less worked up about what pathologies would result from a Condorcet cycle than i am about what pathologies result from FPTP or IRV (or Borda or whoever) failing to elect the Condorcet winner whether such exists. we know the latter actually happens in governmental elections. i still have my doubts to any significant prevalence of the former. on the rare occasion a cycle ever happens, probably Tideman Ranked- Pairs would be the best compromise between a fairer Schulze beatpath and some method that has sufficient "lucidity" that voters can understand it and have confidence that no "funny business" is going on. but whether it's beatpath or ranked-pairs or IRV rules as the method that resolves a cycle, at least in this very rare occasion, it's picking a non-Condorcet winner meaningfully, even if there are conceptual ways to turn tactical with it. but then, how profitable is it to vote tactically when there is little probability to the conditions that would serve such tactical voting? if it were one of those Condorcet methods and if there is little likelihood of a cycle happening and if a savvy voter knows that, how does it benefit his/her political interests to do anything other than vote for their fav as their first choice and cover their ass with a tolerable 2nd choice? how are they ever (assuming no cycle) hurting their favorite or helping any unranked candidates (tied for last place, in this voter's esteem) beat the 2nd choice? i really find it hard to see the tactical interests as differing from the sincere political interests. r b-j Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] strategy-free Condorcet method after all!
> robert bristow-johnson wrote: ... >> i dunno how to, other than take the raw ballot data of some existing IRV >> elections, but i would like to see how many of these municipal IRV >> elections, that if the ballots were tabulated according to Condorcet >> rules, that a cycle would occur. Kristofer Munsterhjelm wrote: ... > I haven't run the data through my simulator yet, but it seems cycles are > rare. i have to confess that i am less worked up about what pathologies would result from a Condorcet cycle than i am about what pathologies result from FPTP or IRV (or Borda or whoever) failing to elect the Condorcet winner whether such exists. we know the latter actually happens in governmental elections. i still have my doubts to any significant prevalence of the former. on the rare occasion a cycle ever happens, probably Tideman Ranked-Pairs would be the best compromise between a fairer Schulze beatpath and some method that has sufficient "lucidity" that voters can understand it and have confidence that no "funny business" is going on. but whether it's beatpath or ranked-pairs or IRV rules as the method that resolves a cycle, at least in this very rare occasion, it's picking a non-Condorcet winner meaningfully, even if there are conceptual ways to turn tactical with it. but then, how profitable is it to vote tactically when there is little probability to the conditions that would serve such tactical voting? if it were one of those Condorcet methods and if there is little likelihood of a cycle happening and if a savvy voter knows that, how does it benefit his/her political interests to do anything other than vote for their fav as their first choice and cover their ass with a tolerable 2nd choice? how are they ever (assuming no cycle) hurting their favorite or helping any unranked candidates (tied for last place, in this voter's esteem) beat the 2nd choice? i really find it hard to see the tactical interests as differing from the sincere political interests. r b-j Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] strategy-free Condorcet method after all!
Andrew Myers wrote: I have ballot data from about 1500 elections run using CIVS. But I haven't had the time to write software to package it up nicely. Could you use CIVS itself to quickly determine how many of them had proper Condorcet winners (i.e. Smith set of cardinality one)? That might be an interesting result and wouldn't take as long time as packaging up the data. Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] strategy-free Condorcet method after all!
Kristofer Munsterhjelm wrote: Warren Smith has a copy of Tideman's election archive, as well as some other data, here: http://rangevoting.org/TidemanData.html I haven't run the data through my simulator yet, but it seems cycles are rare. There's also a database of STV elections at http://www.openstv.org/stvdb . While they could be processed by my program (if I write the correct converters), they are multiwinner elections and so the frequency of cycles might not be relevant to what would be the case for when voters are told the election is single-winner. Does anybody know of any data sources apart from the above? I have ballot data from about 1500 elections run using CIVS. But I haven't had the time to write software to package it up nicely. -- Andrew Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] strategy-free Condorcet method after all!
robert bristow-johnson wrote: On Nov 23, 2009, at 1:43 AM, Dave Ketchum wrote: Seems to me that cycles can occur even with sincerity - they relate to conflict among three or more voter views. sure, they "can". but i still question the prevalence of such happening. and with the other methods, particularly the two used in governmental elections: FPTP and IRV, the prevalence of tactical voting (particularly compromising) is clear. why is there so much worry about a pathology that just doesn't seem to occur often enough to be worth it when there seems to be plenty reason to worry about pathologies involved with the non-Condorcet methods? i dunno how to, other than take the raw ballot data of some existing IRV elections, but i would like to see how many of these municipal IRV elections, that if the ballots were tabulated according to Condorcet rules, that a cycle would occur. i know the answer for Burlington 2006 and 2009 (no cycle in either case, the first case the IRV, Condorcet, and FPTP winner was the same person, the second case they were 3 different persons, a clear pathology worth worrying about). what about Cambridge MA or SF, anyone know? Warren Smith has a copy of Tideman's election archive, as well as some other data, here: http://rangevoting.org/TidemanData.html I haven't run the data through my simulator yet, but it seems cycles are rare. There's also a database of STV elections at http://www.openstv.org/stvdb . While they could be processed by my program (if I write the correct converters), they are multiwinner elections and so the frequency of cycles might not be relevant to what would be the case for when voters are told the election is single-winner. Does anybody know of any data sources apart from the above? Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] strategy-free Condorcet method after all!
On Nov 23, 2009, at 1:43 AM, Dave Ketchum wrote: Seems to me that cycles can occur even with sincerity - they relate to conflict among three or more voter views. sure, they "can". but i still question the prevalence of such happening. and with the other methods, particularly the two used in governmental elections: FPTP and IRV, the prevalence of tactical voting (particularly compromising) is clear. why is there so much worry about a pathology that just doesn't seem to occur often enough to be worth it when there seems to be plenty reason to worry about pathologies involved with the non-Condorcet methods? i dunno how to, other than take the raw ballot data of some existing IRV elections, but i would like to see how many of these municipal IRV elections, that if the ballots were tabulated according to Condorcet rules, that a cycle would occur. i know the answer for Burlington 2006 and 2009 (no cycle in either case, the first case the IRV, Condorcet, and FPTP winner was the same person, the second case they were 3 different persons, a clear pathology worth worrying about). what about Cambridge MA or SF, anyone know? -- r b-j r...@audioimagination.com "Imagination is more important than knowledge." Election-Methods mailing list - see http://electorama.com/em for list info
