Re: [EM] SODA might be the method we've been looking for.
2011/12/15 Andrew Myers an...@cs.cornell.edu On 7/22/64 2:59 PM, Andy Jennings wrote: I don't see any huge theoretical downsides. Do others still have reservations about SODA? I realize that some people may be opposed to delegation, in principle. And others think delegable systems just don't have a chance of getting implemented. So I think these debates about which is the best voting system in the standard (non-delegable) model are still useful. I also think it's useful for Jameson to inject a plug about SODA every now and then. I will repeat what I've written before: I have to agree. SODA to me seems quite complex. It appears to pose difficult strategic decisions for candidates and even for voters. Thanks for the honest response. What do you think would help alleviate this largely-false appearance? Voter strategy is limited to a few cases: 1. Correct approval strategy in case your favorite candidate's preferences differ significantly from yours. People on this list understand approval strategy; in my opinion, it's not ideal, but it's no worse than plurality strategy, which most people tolerate. And I estimate that perhaps a third or fewer voters will differ significantly from their favorite candidates. If significantly only counts differences in the order between the two frontrunner candidates, that kind of number makes sense. 2. Attempts at chicken strategy in a few cases. In the classic A+B vs C case, such strategy can only work if C has no preference between A and B. (Under one rule variant of SODA, even an honest preference that wasn't predeclared would be sufficient to avoid a chicken dilemma). Note that, unlike in approval/Range/MJ, the only way a chicken strategy can work for A is by making it impossible for B to win the election; chicken strategy is * always* either ineffective or dangerous. So it seems to me that in SODA, unlike those systems, there is no slippery slope to a chicken dilemma. As for candidate strategy, that comes in two flavors: 1. Preference declaration strategies. Again, these mainly come down to chicken strategies, and there are several restraints even on such strategies. If A truncates B, B can retaliate; this should keep it from happening unless A is clearly a second-string candidate, in which case it may be a good thing. Also, C could intervene to avoid the dilemma. 2. Post-election strategy. This is a sequential, perfect-information game; there's a single optimal strategy, and in any real election it's pretty easy to calculate. (I can imagine artificially-balanced situations with dozens or hundreds of candidates which might be NP-hard; but in real life, it basically comes down to finding the delegated CW). Also note that journalists would quickly work out and publish the optimal strategy and all plausible variations thereof, so the candidates would not have to work it out on their own. So, I can't quite give a blanket denial that strategy matters, but I can give a qualified one: in real life SODA elections, it is not worth worrying about strategy. Having read the above, can you see any way I could say that better? I want to be able to allay this concern; strategy issues are an outstanding strength of SODA, not a weakness. Jameson Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] SODA might be the method we've been looking for.
One kind of SODA strategy which I didn't discuss is candidate preference-declaration strategy aimed, not at directly attaining a better result, but at attracting votes. This would basically take two forms: established candidates truncating upstarts to try to minimize their importance, and a candidate altering their true preference order to better conform to some important fraction (probably the majority) of their voters. In both cases, these phenomena would tend to have a bandwagon effect which is arguably socially beneficial - minimizing the chances that a weak Condorcet winner will win the election, while strengthening the margin of true Condorcet winners. So I'm not worried about this sort of strategy being a problem. Jameson 2011/12/15 Jameson Quinn jameson.qu...@gmail.com 2011/12/15 Andrew Myers an...@cs.cornell.edu On 7/22/64 2:59 PM, Andy Jennings wrote: I don't see any huge theoretical downsides. Do others still have reservations about SODA? I realize that some people may be opposed to delegation, in principle. And others think delegable systems just don't have a chance of getting implemented. So I think these debates about which is the best voting system in the standard (non-delegable) model are still useful. I also think it's useful for Jameson to inject a plug about SODA every now and then. I will repeat what I've written before: I have to agree. SODA to me seems quite complex. It appears to pose difficult strategic decisions for candidates and even for voters. Thanks for the honest response. What do you think would help alleviate this largely-false appearance? Voter strategy is limited to a few cases: 1. Correct approval strategy in case your favorite candidate's preferences differ significantly from yours. People on this list understand approval strategy; in my opinion, it's not ideal, but it's no worse than plurality strategy, which most people tolerate. And I estimate that perhaps a third or fewer voters will differ significantly from their favorite candidates. If significantly only counts differences in the order between the two frontrunner candidates, that kind of number makes sense. 2. Attempts at chicken strategy in a few cases. In the classic A+B vs C case, such strategy can only work if C has no preference between A and B. (Under one rule variant of SODA, even an honest preference that wasn't predeclared would be sufficient to avoid a chicken dilemma). Note that, unlike in approval/Range/MJ, the only way a chicken strategy can work for A is by making it impossible for B to win the election; chicken strategy is *always* either ineffective or dangerous. So it seems to me that in SODA, unlike those systems, there is no slippery slope to a chicken dilemma. As for candidate strategy, that comes in two flavors: 1. Preference declaration strategies. Again, these mainly come down to chicken strategies, and there are several restraints even on such strategies. If A truncates B, B can retaliate; this should keep it from happening unless A is clearly a second-string candidate, in which case it may be a good thing. Also, C could intervene to avoid the dilemma. 2. Post-election strategy. This is a sequential, perfect-information game; there's a single optimal strategy, and in any real election it's pretty easy to calculate. (I can imagine artificially-balanced situations with dozens or hundreds of candidates which might be NP-hard; but in real life, it basically comes down to finding the delegated CW). Also note that journalists would quickly work out and publish the optimal strategy and all plausible variations thereof, so the candidates would not have to work it out on their own. So, I can't quite give a blanket denial that strategy matters, but I can give a qualified one: in real life SODA elections, it is not worth worrying about strategy. Having read the above, can you see any way I could say that better? I want to be able to allay this concern; strategy issues are an outstanding strength of SODA, not a weakness. Jameson Election-Methods mailing list - see http://electorama.com/em for list info
[EM] Simple SODA strategy (post-election delegated phase)
Here's a simple strategy rule of thumb. I don't claim it's perfect strategy in all cases, but it is in all the cases I've checked. When it is your turn to assign delegated votes, find the current Smith set (that is, counting all unassigned delegated ballots, including the ones delegated to you, as preferences; and all undelegated or already-assigned ballots as approvals). Approve all candidates whom you prefer to at least one member of that set. As for the last member(s) of that set, approve them if and only if, without your vote, (all of) your most-preferred member(s) of the set would no longer be in the Smith set. (The parenthetical plurals are to cover the case where you are indifferent between certain members of the Smith set.) Obviously, this strategy would be simpler to state in the common case where there is a CW, that is, a one-member Smith set. Basically, assign approval for everyone you prefer to the CW, and include the CW only if they need your vote to win. And the result is almost always that the CW wins (except in some cases with clonesets of 3 or more). Again, this may be perfect strategy only (conservatively) 99% of the time; but in the extremely rare case that it's not, I would expect somebody in academia or the press to realize and publish that information in time for the candidates to use correct strategy. Jameson Election-Methods mailing list - see http://electorama.com/em for list info
[EM] Chris: Regarding the criteriion failures you mentioned for MMT
Chris: You said that MMT fails Mono-Add-Plump: I've already commented on that a few times. You said that MMT fails Condorcet's Criterion: But, as you know, CC is incompatible with FBC. You said that MMT fails Mutual Dominant 3rd: I don't know what that criterion is. But, in any case, to say that a failure of it is important, you'd have to justify the criterion in terms of something of (preferably) practical importance. You said that MMT fails Minimal Defense: Plurality meets Minimal Defense. So my answer will refer to the universally-applicable counterpart to Minimal Defense: 1CM. Of course MMT fails 1CM. MMT doesn't recognize one-sided coalitions. Rather than being an accidental failure, that is the point of MMT. To justify using 1CM against MMT, you'd need to tell why it's necessary to recognize one-sided coalitions. You'd need to justify it other than in terms of a criterion requiring that recognition. You said that MMT fails Later-No-Help: With MMT, you can help your favorite by entering into a mutually-chosen, mutually-supported, majority coalition. Everyone supporting that coalition does so because they consider it beneficial to their interest. How is that a failure?? In summary, you're citing those criteria as if their compliance is necessary, for its own sake. But when you do that, you need to say _why_ their compliance is necessary for its own sake. For one thing, that depends on what we want. If we choose MMT, we don't want one-sided support within a majority set of factions to be counted, when that would mean You help, you lose. Of course you could say that you don't want to avoid the cooperation/defection problem, and then tell why. As Jameson said in August, the chicken dilemma, also called the co-operation/defection problem, or the ABE problem, is the most difficult strategy problem to get rid of. However, there are a number of methods that do get rid of it, while complying with FBC and furnishing majority-rule protection: SODA, and several non-delegating methods: MMT, MTAOC, MMPO, MDDTR, and maybe a few others. Forest has just proposed one today, and so I haven't yet had the opportunity to study it. You (Chris) proposed one some time ago. Does it meet the criteria that you require, in addition to FBC and avoidance of the co-operation/defection problem? Can it be worded in a brief and simple, and naturally and obviously motivated way, for public propsal? We often cite criteria here. But, to a member of the public who looks here to evaluate a method proposed in hir jurisdiction, that will be a confusing jumble of mutually-contradictory requirements. That's why it's important that we also discuss _why_ we claim that a particular criterion is important. For instance, I've told why FBC is essential in the U.S. And I've told why it's important to avoid the co-operation/defection problem. Mike Ossipoff Election-Methods mailing list - see http://electorama.com/em for list info
[EM] Chris: Regarding the criteriion failures you mentioned for MMT
Chris: You said that MMT fails Mono-Add-Plump: I've already commented on that a few times. You said that MMT fails Condorcet's Criterion: But, as you know, CC is incompatible with FBC. You said that MMT fails Mutual Dominant 3rd: I don't know what that criterion is. But, in any case, to say that a failure of it is important, you'd have to justify the criterion in terms of something of (preferably) practical importance. You said that MMT fails Minimal Defense: Plurality meets Minimal Defense. So my answer will refer to the universally-applicable counterpart to Minimal Defense: 1CM. Of course MMT fails 1CM. MMT doesn't recognize one-sided coalitions. Rather than being an accidental failure, that is the point of MMT. To justify using 1CM against MMT, you'd need to tell why it's necessary to recognize one-sided coalitions. You'd need to justify it other than in terms of a criterion requiring that recognition. You said that MMT fails Later-No-Help: With MMT, you can help your favorite by entering into a mutually-chosen, mutually-supported, majority coalition. Everyone supporting that coalition does so because they consider it beneficial to their interest. How is that a failure?? In summary, you're citing those criteria as if their compliance is necessary, for its own sake. But when you do that, you need to say _why_ their compliance is necessary for its own sake. For one thing, that depends on what we want. If we choose MMT, we don't want one-sided support within a majority set of factions to be counted, when that would mean You help, you lose. Of course you could say that you don't want to avoid the cooperation/defection problem, and then tell why. As Jameson said in August, the chicken dilemma, also called the co-operation/defection problem, or the ABE problem, is the most difficult strategy problem to get rid of. However, there are a number of methods that do get rid of it, while complying with FBC and furnishing majority-rule protection: SODA, and several non-delegating methods: MMT, MTAOC, MMPO, MDDTR, and maybe a few others. Forest has just proposed one today, and so I haven't yet had the opportunity to study it. You (Chris) proposed one some time ago. Does it meet the criteria that you require, in addition to FBC and avoidance of the co-operation/defection problem? Can it be worded in a brief and simple, and naturally and obviously motivated way, for public propsal? We often cite criteria here. But, to a member of the public who looks here to evaluate a method proposed in hir jurisdiction, that will be a confusing jumble of mutually-contradictory requirements. That's why it's important that we also discuss _why_ we claim that a particular criterion is important. For instance, I've told why FBC is essential in the U.S. And I've told why it's important to avoid the co-operation/defection problem. Mike Ossipoff Election-Methods mailing list - see http://electorama.com/em for list info
[EM] Chris: Regarding the criteriion failures you mentioned for MMT
Chris: You said that MMT fails Mono-Add-Plump: I've already commented on that a few times. You said that MMT fails Condorcet's Criterion: But, as you know, CC is incompatible with FBC. You said that MMT fails Mutual Dominant 3rd: I don't know what that criterion is. But, in any case, to say that a failure of it is important, you'd have to justify the criterion in terms of something of (preferably) practical importance. You said that MMT fails Minimal Defense: Plurality meets Minimal Defense. So my answer will refer to the universally-applicable counterpart to Minimal Defense: 1CM. Of course MMT fails 1CM. MMT doesn't recognize one-sided coalitions. Rather than being an accidental failure, that is the point of MMT. To justify using 1CM against MMT, you'd need to tell why it's necessary to recognize one-sided coalitions. You'd need to justify it other than in terms of a criterion requiring that recognition. You said that MMT fails Later-No-Help: With MMT, you can help your favorite by entering into a mutually-chosen, mutually-supported, majority coalition. Everyone supporting that coalition does so because they consider it beneficial to their interest. How is that a failure?? In summary, you're citing those criteria as if their compliance is necessary, for its own sake. But when you do that, you need to say _why_ their compliance is necessary for its own sake. For one thing, that depends on what we want. If we choose MMT, we don't want one-sided support within a majority set of factions to be counted, when that would mean You help, you lose. Of course you could say that you don't want to avoid the cooperation/defection problem, and then tell why. As Jameson said, the chicken dilemma, also called the co-operation/defection problem, or the ABE problem, is the most difficult strategy problem to get rid of. However, there are a number of methods that do get rid of it, while complying with FBC and furnishing majority-rule protection: SODA, and several non-delegating methods: MMT, MTAOC, MMPO, MDDTR, and maybe a few others. Forest has just proposed one today, and so I haven't yet had the opportunity to study it. You (Chris) proposed one some time ago. Does it meet the criteria that you require, in addition to FBC and avoidance of the co-operation/defection problem? Can it be worded in a brief and simple, and naturally and obviously motivated way, for public propsal? We often cite criteria here. But, to a member of the public who looks here to evaluate a method proposed in hir jurisdiction, that will be a confusing jumble of mutually-contradictory requirements. That's why it's important that we also discuss _why_ we claim that a particular criterion is important. For instance, I've told why FBC is essential in the U.S. And I've told why it's important to avoid the co-operation/defection problem. Mike Ossipoff Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Electoral Experimentation
On 12/15/2011 12:15 PM, David L Wetzell wrote: dlw: Within the third parties themselves, there'd need to be used single-winner elections to determine their candidates/leaders/positions. In these regards, there'd be great scope for experimentation with single-winner election rules, especially since they'd have no commitment to a particular single-winner election rule. You said that experimentation opportunities would be a good reason to strategically support IRV. Presumably IRV would be used for both internal voting to determine their candidates/leaders/positions and for choosing candidates for public elections. Why would IRV-chosen party leaders be motivated to try any other voting method (for either internal or candidate-selection use)? Richard Fobes On 12/15/2011 12:15 PM, David L Wetzell wrote: -- Forwarded message -- From: Richard Fobes electionmeth...@votefair.org To: election-meth...@electorama.com mailto:election-meth...@electorama.com Cc: Date: Wed, 14 Dec 2011 23:26:59 -0800 Subject: [EM] Electoral experimentation On 12/14/2011 12:59 PM, David L Wetzell wrote: if we push hard for the use of American Proportional Representation it'll give third parties a better chance to win seats and they will prove great labs for experimentation with electoral reform. This is also a good reason to strategically support IRV, since we can trust that with changes, there'll be more scope for experimentation and consideration of multiple alternatives to FPTP. dlw I doubt that electoral experimentation would follow the adoption of any new election method. Why? Consider that elected representatives tend to defend whatever election method they got elected under. So if American Proportional Representation -- or any other method -- were used by a third party to elect its leaders, the elected representatives would be unlikely to support experimenting with other election methods. dlw: Within the third parties themselves, there'd need to be used single-winner elections to determine their candidates/leaders/positions. In these regards, there'd be great scope for experimentation with single-winner election rules, especially since they'd have no commitment to a particular single-winner election rule. It's analogous to a door to a treasure room that gets closed and locked after the first people pass through. People who gain access to power naturally want to preserve whatever electoral system got them elected. dlw: Third parties (in a 2 party dominated system) aren't so much about getting into power as making democracy work, turning over the center Richard Fobes Election-Methods mailing list - see http://electorama.com/em for list info Election-Methods mailing list - see http://electorama.com/em for list info
[EM] I didn't mean to post that message 3 times. I was notified that I'd have to re-send.
When I tried to post the message that I just posted, I received a notification that it couldn't be sent because the server was busy, and that I should re-send. Maybe next time, then, I should wait a while before re-sending. Mike Ossipoff Election-Methods mailing list - see http://electorama.com/em for list info
[EM] SODA strategy
If voters think that SODA is complex, then it's because they have been exposed unnecessarily or prematurely to the niceties of strategy considerations. Let's take a lesson from IRV supporters. They don't get anybody worried about IRV's monotonicity failure or FBC failure by bringing them up to unsophisticated voters. We need to emphasize the simplicity of SODA voting to the public, and answer the strategy questions to the experts. Election-Methods mailing list - see http://electorama.com/em for list info
[EM] Electoral Experimentation
-- Forwarded message -- From: Richard Fobes electionmeth...@votefair.org To: election-meth...@electorama.com Cc: Date: Thu, 15 Dec 2011 12:39:23 -0800 Subject: Re: [EM] Electoral Experimentation On 12/15/2011 12:15 PM, David L Wetzell wrote: dlw: Within the third parties themselves, there'd need to be used single-winner elections to determine their candidates/leaders/positions. In these regards, there'd be great scope for experimentation with single-winner election rules, especially since they'd have no commitment to a particular single-winner election rule. Fobes: You said that experimentation opportunities would be a good reason to strategically support IRV. Presumably IRV would be used for both internal voting to determine their candidates/leaders/positions and for choosing candidates for public elections. dlw: There'd be no need for such. The point is that if there were many LTPs, local third parties, they'd have their own rules and could use IRV[or another alternative to FPTP] to choose which rules they'd use for internal voting and the determination of their candidates in elections. Why would IRV-chosen party leaders be motivated to try any other voting method (for either internal or candidate-selection use)? dlw: Because it'd be the American forms of PR, not IRV, that would give the LTPs license to win representation and to have more voice. I said strategically support IRV for single-winner, not because it's a god-send but because bickering endlessly about the best single-winner election rule takes away from pushing for the aforementioned reform that would then bring about many venues for electoral experimentation. There's no good reason to presuppose that these smaller parties would be beholden to IRV so as not to consider other options. And that is why it's worthwhile to put aside the infinite number of other election rules and focus on getting Am forms of PR plus IRV as key parts of the renewal of the US's democracy. dlw Richard Fobes Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] SODA strategy
2011/12/15 fsimm...@pcc.edu If voters think that SODA is complex, then it's because they have been exposed unnecessarily or prematurely to the niceties of strategy considerations. Let's take a lesson from IRV supporters. They don't get anybody worried about IRV's monotonicity failure or FBC failure by bringing them up to unsophisticated voters. In fact, they disingenuously use IRV's LNH compliance to claim that no strategy is needed. Is there some criterion we could use to more-honestly say that strategy is practically-speaking irrelevant in SODA? Unfortunately, SODA does not meet the letter of the SFC, which has the best name of any criterion. (Though I'd argue that SODA meets the spirit of the SFC. It fails both because non-delegated votes don't allow full preferences, and because large clonesets can obscure a true CW and trip up the delegated-assignment order algorithm. But both of these are technicalities in my opinion.) For instance, the unique-FBC for 3 serious candidates is a guarantee that it is safe to bullet vote (delegate). But if we're going to make a big deal out of that criterion, it definitely needs a better name. We need to emphasize the simplicity of SODA voting to the public, and answer the strategy questions to the experts. Election-Methods mailing list - see http://electorama.com/em for list info Election-Methods mailing list - see http://electorama.com/em for list info
[EM] FBC failure for acquiescing coalition methods
Mike,
I think your example applies to all acquiescing coalition methods that we have
considered. The failure is
caused by someone leap frogging over others to get to the top position.
But I think that most of these methods satisfy this FBC like property:
If the winner changes when (on some ballot) candidate X is moved to the top
slot along with all of the
candidates that were ranked above X, then the new winner will be X or one of
the other candidates that
were raised on that ballot.
This seems like a reasonable substitue for the FBC, since it builds into it a
consistency requirement,
namely that if you raise X. then sincerity requires raising to the same level
or higher all candidates that
you prefer over X.
Forest
From: MIKE OSSIPOFF
To:
Subject: [EM] Forest: I found an FBC failure for Minimal Aquiescing
Majorities-Top
Message-ID:
Content-Type: text/plain; charset=iso-8859-1
Forest--
Say it's like the ABE, except that there's one more candidate, D.
In the ABE, you were an A voter, but now, with D in the
election, you like D best,
with A your 2nd choice.
(Say all the A voters vote as you do)
The B voters, while willing to middle-rate A for a majority
coalition, wouldn't
be willing to miiddle-rate D.
If you vote A D together in 1st place, then your top-rating
for D means that
{A,B} is no longer a winning set, because you vote D over B.
If you vote in that way, C wins.
But you can at least make A win, because the B voters are
willing to middle-rate A.
You can do that by top-rating only A. You can middle-rate D if
you want to.
Then, {A,B} wins, and, in that set, A wins with the most top votes.
You can get your best possible outcome (the election of A) only
by voting someone over
your favorite.
Mike Ossipoff
Election-Methods mailing list - see http://electorama.com/em for list info
