Yes, the definition of Simmons' method, MDDA(pt/2) should be added to Electowiki. Should Forest get the first option to do that? Michael Ossipoff On Mon, Nov 21, 2016 at 6:29 PM, Monkey Puzzle <araucaria.araucana@gmail.com > wrote: > Forest, Michael, Chris: > > It seems that you are converging toward consensus on a modified version of > ICA that is equivalent to MDDTR(pt/2), if > > Both these methods have scattered definitions on the list that go back > years, and the current discussion has moved toward something different than > the ICA description here: http://wiki.electorama.com/ > wiki/Improved_Condorcet_Approval . > > Would it be possible to have a concise restatement/correction of the > method(s) somewhere, preferably on electorama? > > Thank you! > > Frango ut patefaciam -- I break so that I may reveal > > On Mon, Nov 21, 2016 at 3:03 PM, Michael Ossipoff <email9648742@gmail.com> > wrote: > >> "Just the knowledge that a failure of Mono-add-Plump is theoretically >> possible could reduce people's enthusiasm for voting and make it more >> likely that those who like to vote by just plumping for their favourite >> will stay home." >> >> ...or make you rank your favorite last instead of first in IRV because >> ranking hir first instead of last could make hir lose? >> >> ...or just not vote because you know that IRV can act oppositely to >> changes in your vote? >> >> Michael Ossipoff >> >> On Sat, Nov 19, 2016 at 12:18 AM, C.Benham <cbenham@adam.com.au> wrote: >> >>> On 11/19/2016 3:14 AM, Michael Ossipoff wrote: >>> >>> If the more embarrassing Mono-Raise failure doesn't give IRV any >>> acceptance or enactment problem, then why should the less embarrassing >>> Mono-Add-Plump failure of MDDTR give MDDTR an acceptance or enactment >>> problem? >>> >>> >>> Because what you consider more or less "embarrassing" I am sure isn't in >>> accord with what most people would find unacceptably ridiculous. >>> >>> With MDDTR, if your plump for X makes X lose, it's because you added a >>> ballot. It has nothing whatsoever to do with the fact that you voted >>> favorably to X. >>> >>> >>> That's right. "You" should have found some way to vote for X without >>> adding a ballot. Unfortunately removing someone else's ballot when you are >>> in the >>> polling station is usually impossible or legally risky. >>> >>> Anyway, if IRV is so widely used and successful, then why would >>> nonmonotonicity be a problem for MDDTR? >>> >>> >>> Because IRV has a traditional and (for many) intuitive algorithm, and a >>> solid "maximal" set of criterion compliances and MDDTR doesn't. >>> >>> Earlier you attempted to ridicule my observation that MDDTR fails >>> Irrelevant Ballots Independence by suggesting that might indirectly >>> motivate a higher >>> turnout. Well, just as some might have an interest in promoting that >>> (for voters who'll ignore the competitive/viable candidates) so as to wash >>> away >>> an otherwise likely majority-defeat disqualification so would opposed >>> forces have an interest in doing the opposite. >>> >>> In fact you could have post-election recriminations reminiscent of those >>> that were aimed at Nader and those who voted for him supposedly allowing >>> Bush to >>> win a few years ago. "Those idiots weren't even really interested in who >>> won, why didn't they just stay home?!" could be the lament. >>> >>> Just the knowledge that a failure of Mono-add-Plump is theoretically >>> possible could reduce people's enthusiasm for voting and make it more >>> likely that those who like to vote by just plumping for their favourite >>> will stay home. >>> >>> Whereas IRV doesn't just meet mono-add-plump. It also meet Mono-add-Top. >>> >>> C: Failing mono-add-plump is as stupid as a quasi-"intelligent" device >>> can be, in a pure and starkly obvious way, and with the lamest possible >>> excuse. >>> >>> The algorithm/device decides that X should win, and then receives some >>> more ballots that contain nothing whatsoever but the pure and simple >>> message: >>> "You are right! X should win" and responds with the bizarre malfunction >>> "I've changed my mind, Y should win" and offers the nonsensical excuse "Hey >>> those >>> extra ballots didn't just say that X should win. They also increased the >>> total number of ballots!". >>> >>> >>> C: What (arguably) desirable properties (or criterion compliances) are >>> incompatible with meeting Mono-add-Plump? >>> >>> Mike: FBC, CD, & wv-like strategy are evidently require failing >>> Mono-Add-Plump, or having MMPO's Hitler-with-2-votes problem. >>> >>> With MDDTR, the price of FBC, CD & wv-like strategy is Mono-Add-Plump. >>> >>> >>> C: There are methods that meet FBC and CD and mono-add-plump. So your >>> proposition boils down to saying that it's worth giving up compliance with >>> mono-add-plump just to gain "wv-like strategy". >>> >>> >>> Chris Benham >>> >>> >>> >>> On 11/19/2016 3:14 AM, Michael Ossipoff wrote: >>> >>> I don't mean that IRV isn't ok. IRV's Mono-Raise failure doesn't bother >>> me. >>> Neither does MDDTR's Mono-Add-Plump failure. >>> >>> Voting's purpose is probabilistic anyway. You vote to improve the >>> probability of a better outcome. The possible nonmonotonicity of IRV >>> & MDDTR doesn't invalidate that. >>> >>> My point, in asking about when you make someone lose by raising hir from >>> last place to 1st place, was just that IRV is popular and widely used. It's >>> been used in Australia for a long time, and it's used in a fair number of >>> cities in this country. ...and now has been adopted by the state of Maine. >>> >>> ...in spite of its Mono-Raise failure. >>> >>> If the more embarrassing Mono-Raise failure doesn't give IRV any >>> acceptance or enactment problem, then why should the less embarrassing >>> Mono-Add-Plump failure of MDDTR give MDDTR an acceptance or enactment >>> problem? >>> >>> There of course have been objections to IRV, some valid, some not. But I >>> haven't heard any of the IRV critics in the various cities complain about >>> its nonmonotonicity. They object to implementation complexity. They >>> invalidly claim voting complexity. They invalidly complain because >>> supposedly voting is supposed to be by Plurality. They repealed IRV in >>> Burlington because of the elimination of a CWv. But none of the >>> complaints that I've heard, in cities using it or considering IRV, have >>> been about its nonmonotonicity. >>> >>> Why I say that Mono-Raise failure is more embarrassing: >>> >>> With MDDTR, if your plump for X makes X lose, it's because you added a >>> ballot. It has nothing whatsoever to do with the fact that you voted >>> favorably to X. >>> >>> With IRV, if raising X from bottom to top makes X lose, then X lost for >>> no other reason than because you helped hir more. >>> >>> There are 2 kinds of nonmonotonicity: >>> >>> Did you make X lose _in spite of_ voting favorably for hir? >>> >>> or >>> >>> Did you make X lose _because_ you voted hir more favorably? >>> >>> Of those 2 kinds of nonmonotonicity the 2nd one is more of an >>> embarrassment to the method. There, the method is more directly acting >>> oppositely to your action. >>> >>> Maybe it could be said that the 2nd kind of nonmonotonicity is twice as >>> embarrassing to the voting-system. >>> >>> Anyway, if IRV is so widely used and successful, then why would >>> nonmonotonicity be a problem for MDDTR? >>> >>> I now feel that IRV's (mitigated) problem isn't an unusually high price >>> for CD, isn't more than the "going rate" for CD. IRV & its derivatives are >>> at the top of my ranking of method-merit for electorates who want &/or need >>> ranking. >>> >>> Michael Ossipoff >>> >>> >>> >>> >>> >>> >>> >>> On Fri, Nov 18, 2016 at 1:23 AM, Michael Ossipoff < >>> email9648742@gmail.com> wrote: >>> >>>> Forest-- >>>> >>>> You wrote: >>>> >>>>> >>>>> But MAI still fails FBC. >>>>> >>>> >>>> Failing both FBC & CD isn't good. >>>> >>>> >>>>> >>>>> So to me the best proposal is ICA with default approval cutoff at >>>>> truncation to help punish burial and truncation with an option to raise the >>>>> cutoff to withstand a CD attack. >>>>> >>>> >>>> But buriers or truncators could raise that approval cutoff too. Someone >>>> could bury X under Z without having to approve Z. That loses the deterrence >>>> that would exist if that burier had to approve Z in order to rank hir over >>>> someone, as would be so if ranking is counted as approval. >>>> >>>> So CD still comes at the cost of a lot less protection against burial, >>>> or, in ICT's case, trunction too. >>>> >>>> But that just means that it isn't _better_ than MDDTR in that regard. >>>> It doesn't mean that it's worse. >>>> >>>> And it doesn't have Mono-Add-Plump failure. >>>> >>>> So, the method has CD as MDDTR does, and trades truncation-proofness >>>> for Mono-Add-Plump. >>>> >>>> I value strategy protections more than embarrassment criteria. (But I >>>> realize that proposal-opponents can use embarrassment criteria criticisms, >>>> and that proponents aren't likely to be able to afford as much media time, >>>> to answer the criticisms.) >>>> >>>> [Replying farther down] : >>>> >>>> >>>> >>>>> >>>>> Here's my version (slightly different from the original): >>>>> >>>>> Candidate X strongly beats candidate Y iff >>>>> >>>>> the number of ballots on which X is ranked over Y is greater than >>>>> >>>>> the number of ballots on which Y is *ranked* equal to or greater than >>>>> Y. >>>>> >>>>> [Note Y is not ranked equal to X if Y is not ranked.] >>>>> >>>>> If not all of the candidates are strongly beaten, disqualify all of >>>>> the ones who are. >>>>> >>>>> Elect the most approved qualified candidate. >>>>> >>>>> I think that this method has all of the good properties of MDDA with >>>>> mono-add-plump to boot. >>>>> >>>> >>>> I've only had a preliminary look at it, but it seems to me, right now, >>>> that the separate approval-cutoff that the voter can raise from the default >>>> spoils protection from burial & truncation. >>>> >>>> >>>> You wrote: >>>> >>>> >>>>> We still need to explore MDDA with the half power truncation rule, >>>>> since it would also satisfy mono-add-plump if I am not mistaken. >>>>> >>>> >>>> Yes, it seems to me that a 1/2 power-truncation would get rid of the >>>> Mono-Add-Plump failure. If, by not ranking a certain 2 candidates, you give >>>> them each at least half of a vote against eachother, that would bring >>>> Mono-Add-Plump compliance, it seems to me. >>>> >>>> So maybe it would avoid criticism of MDDA. >>>> >>>> But, if used with MDDTR, it would spoil CD. >>>> >>>> You wrote: >>>> >>>> >>>> >>>>> I agree with Chris Benham that mono-add-plump failure would be fatal >>>>> in a public proposal. >>>>> >>>>> >>>> What if you're going to rank X last in your ranking. With all the >>>> ballots, including yours, X will win. But then you move X to 1st place in >>>> your ranking, and that makes X lose. >>>> >>>> Would that be ok? >>>> >>>> Michael Ossipoff >>>> >>>> >>>> >>>> >>>>> On Thu, Nov 17, 2016 at 2:12 PM, Michael Ossipoff < >>>>> email9648742@gmail.com> wrote: >>>>> >>>>>> I meant to ask: Did you say that MTRI doesn't pass FBC? How does FBC >>>>>> failure happen? In return for FBC, it should beat MDDTR at vulnerability to >>>>>> burial, and not be vulnerable to truncation. >>>>>> >>>>>> Anyway, anything you can tell me about the properties comparison >>>>>> between MTRI & MDDTR would be helpful. >>>>>> >>>>>> MIchael Ossipoff >>>>>> >>>>>> On Thu, Nov 17, 2016 at 5:05 PM, Michael Ossipoff < >>>>>> email9648742@gmail.com> wrote: >>>>>> >>>>>>> For this method, MTRI, the procedural definition is more >>>>>>> understandable than the recursive definition (though the recursive >>>>>>> definition's brevity could be useful). >>>>>>> >>>>>>> So this is what I understand MTRI's procedural definition to be: >>>>>>> >>>>>>> 1. Order the candidates by their top-count score, with higher scores >>>>>>> at top. >>>>>>> >>>>>>> 2. Switch the lowest pair of adjacent candidates whose lower >>>>>>> candidate pair-beats the higher one. >>>>>>> >>>>>>> Repeat till there are no more pairs to switch. The highest candidate >>>>>>> in the order at that time wins. >>>>>>> >>>>>>> ----------------------------------------------- >>>>>>> >>>>>>> As a CD rank method, this method is a competitor of MDDTR. What are >>>>>>> the property differences between MTRI & MDDTR? >>>>>>> >>>>>>> In particular, how does MTRI compare with MDDTR in regards to >>>>>>> protection of a CWs against truncation & burial? >>>>>>> >>>>>>> Michael Ossipoff >>>>>>> >>>>>>> >>>>>>> On Thu, Nov 17, 2016 at 2:55 PM, Forest Simmons <fsimmons@pcc.edu> >>>>>>> wrote: >>>>>>> >>>>>>>> On Thu, Nov 17, 2016 at 10:54 AM, Michael Ossipoff < >>>>>>>> email9648742@gmail.com> wrote: >>>>>>>> >>>>>>>>> But wouldn't Smith//Approval, with approval cutoffs in the >>>>>>>>> rankings, share MDDTR's burial-vullnerability? >>>>>>>>> >>>>>>>>> ...with, additionally, vulnerability to truncation, which MDDTR >>>>>>>>> _doesn't_ have? >>>>>>>>> >>>>>>>>> And Smith//Approval trades MDDTR's FBC for Smith, which I consider >>>>>>>>> an unfavorable trade. >>>>>>>>> >>>>>>>> >>>>>>>> Perhaps make truncation the default approval cutoff, but let voters >>>>>>>> move it higher as an option: >>>>>>>> >>>>>>>> 45 C >>>>>>>> 30 A>B or A>>B >>>>>>>> 25 B >>>>>>>> >>>>>>>> Voting A>>B would be the chicken defense (where sincere is 25 B>A). >>>>>>>> >>>>>>>> Voting A>B would be the truncation defense (where sincere is 45 >>>>>>>> C>B). >>>>>>>> >>>>>>>> With this option, MDDA would be an FBC compliant method that is >>>>>>>> truncation and burial resistant as well as quasi CD compliant. >>>>>>>> >>>>>>>> Is there a way to modify MDDA to make it satisfy mono-add-plump? >>>>>>>> >>>>>>>> How about incorporating some form of power truncation. When you >>>>>>>> plump X and reduce the majority victory of Y over Z to a sub-majority, it >>>>>>>> would revert to a majority if you counted the common truncation of Y and Z >>>>>>>> against each other as even half a point. >>>>>>>> >>>>>>>> Btw, in case you didn't see it, one of my new favorite non-FBC >>>>>>>> methods is Most Approved Immune(MAI): Elect the most approved immune >>>>>>>> candidate. >>>>>>>> >>>>>>>> This means elect the most approved candidate X that is unbeaten >>>>>>>> pairwise by the candidate that would win (recursively) if the method were >>>>>>>> applied to the same ballot set with X disqualified or withdrawn. >>>>>>>> >>>>>>>> It is the simplest approval based rank method that confers immunity >>>>>>>> from second place complaints on its winners. >>>>>>>> >>>>>>>> It is quasi CD compliant if voters can specify their approval >>>>>>>> cutoffs above the truncation level when they want to. >>>>>>>> >>>>>>>> A top rank version of this method is fully CD compliant: >>>>>>>> >>>>>>>> Elect the Most Top Ranked Immune candidate. (MTRI) >>>>>>>> >>>>>>>> In other words elect the most top ranked candidate X that is >>>>>>>> unbeaten pairwise by the candidate that would win (recursively) if the >>>>>>>> method were applied to the same ballot set with X disqualified or withdrawn. >>>>>>>> >>>>>>>> Forest >>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >>> >>> >> >> ---- >> Election-Methods mailing list - see http://electorama.com/em for list >> info >> >> >

 On 11/19/2016 3:14 AM, Michael Ossipoff wrote:

 If the more embarrassing Mono-Raise failure doesn't give IRV any
 acceptance or enactment problem, then why should the less
 embarrassing Mono-Add-Plump failure of MDDTR give MDDTR an
 acceptance or enactment problem?

 Because what you consider more or less "embarrassing" I am sure
 isn't in accord with what most people would find unacceptably
 ridiculous.

 With MDDTR, if your plump for X makes X lose, it's because you
 added a ballot. It has nothing whatsoever to do with the fact
 that you voted favorably to X.

 That's right. "You" should have found some way to vote for X
 without adding a ballot. Unfortunately removing someone else's
 ballot when you are in the
 polling station is usually impossible or legally risky.

 Anyway, if IRV is so widely used and successful, then why would
 nonmonotonicity be a problem for MDDTR?

 Because IRV has a traditional and (for many) intuitive algorithm

 , and a solid "maximal"  set of criterion compliances and MDDTR
 doesn't.

 Earlier you attempted to ridicule my observation that MDDTR fails
 Irrelevant Ballots Independence by suggesting that might
 indirectly motivate a higher
 turnout.

 Well, just as some might have an interest in promoting that (for
 voters who'll ignore the competitive/viable candidates) so as to
 wash away
 an otherwise likely majority-defeat disqualification so would
 opposed forces have an interest in doing the opposite.

 I don't mean that IRV isn't ok. IRV's Mono-Raise failure doesn't
 bother me.
 Neither does MDDTR's Mono-Add-Plump failure.

 Voting's purpose is probabilistic anyway. You vote to improve the
 probability of a better outcome. The possible nonmonotonicity of IRV
 & MDDTR doesn't invalidate that.

 My point, in asking about when you make someone lose by raising
 hir from last place to 1st place, was just that IRV is popular
 and widely used. It's been used in Australia for a long time, and
 it's used in a fair number of cities in this country.  ...and now
 has been adopted by the state of Maine.

 ...in spite of its Mono-Raise failure.

 If the more embarrassing Mono-Raise failure doesn't give IRV any
 acceptance or enactment problem, then why should the less
 embarrassing Mono-Add-Plump failure of MDDTR give MDDTR an
 acceptance or enactment problem?

 There of course have been objections to IRV, some valid, some
 not. But I haven't heard any of the IRV critics in the various
 cities complain about its nonmonotonicity. They object to
 implementation complexity. They invalidly claim voting
 complexity. They invalidly complain because supposedly voting is
 supposed to be by Plurality. They repealed IRV in Burlington
 because of the elimination of a CWv.   But none of the complaints
 that I've heard, in cities using it or considering IRV, have been
 about its nonmonotonicity.

 Why I say that Mono-Raise failure is more embarrassing:

 With MDDTR, if your plump for X makes X lose, it's because you
 added a ballot. It has nothing whatsoever to do with the fact
 that you voted favorably to X.

 With IRV, if raising X from bottom to top makes X lose, then X
 lost for no other reason than because you helped hir more.

 There are 2 kinds of nonmonotonicity:

 Did you make X lose _in spite of_ voting favorably for hir?

 or

 Did you make X lose _because_ you voted hir more favorably?

 Of those 2 kinds of nonmonotonicity the 2nd one is more of an
 embarrassment to the method. There, the method is more directly
 acting oppositely to your action.

 Maybe it could be said that the 2nd kind of nonmonotonicity is
 twice as embarrassing to the voting-system.

 Anyway, if IRV is so widely used and successful, then why would
 nonmonotonicity be a problem for MDDTR?

 I now feel that IRV's (mitigated) problem isn't an unusually high
 price for CD, isn't more than the "going rate" for CD. IRV & its
 derivatives are at the top of my ranking of method-merit for
 electorates who want &/or need ranking.

 Michael Ossipoff







 On Fri, Nov 18, 2016 at 1:23 AM, Michael Ossipoff
 <email9648742@gmail.com <mailto:email9648742@gmail.com>> wrote:

     Forest--

     You wrote:


         But MAI still fails FBC.


     Failing both FBC & CD isn't good.


         So to me the best proposal is ICA with default approval
         cutoff at truncation to help punish burial and truncation
         with an option to raise the cutoff to withstand a CD attack.


     But buriers or truncators could raise that approval cutoff
     too. Someone could bury X under Z without having to approve
     Z. That loses the deterrence that would exist if that burier
     had to approve Z in order to rank hir over someone, as would
     be so if ranking is counted as approval.

     So CD still comes at the cost of a lot less protection
     against burial, or, in ICT's case, trunction too.

     But that just means that it isn't _better_ than MDDTR in that
     regard. It doesn't mean that it's worse.

     And it doesn't have Mono-Add-Plump failure.

     So, the method has CD as MDDTR does, and trades
     truncation-proofness for Mono-Add-Plump.

     I value strategy protections more than embarrassment
     criteria. (But I realize that proposal-opponents can use
     embarrassment criteria criticisms, and that proponents aren't
     likely to be able to afford as much media time, to answer the
     criticisms.)

     [Replying farther down] :



         Here's my version (slightly different from the original):

         Candidate X strongly beats candidate Y iff

         the number of ballots on which X is ranked over Y is
         greater than

         the number of ballots on which Y is _/*ranked*/_ equal to
         or greater than Y.

         [Note Y is not ranked equal to X if Y is not ranked.]

         If not all of the candidates are strongly beaten,
         disqualify all of the ones who are.

         Elect the most approved qualified candidate.

         I think that this method has all of the good properties
         of MDDA with mono-add-plump to boot.


     I've only had a preliminary look at it, but it seems to me,
     right now, that the separate approval-cutoff that the voter
     can raise from the default spoils protection from burial &
     truncation.


     You wrote:

         We still need to explore MDDA with the half power
         truncation rule, since it would also satisfy
         mono-add-plump if I am not mistaken.


     Yes, it seems to me that a 1/2 power-truncation would get rid
     of the Mono-Add-Plump failure. If, by not ranking a certain 2
     candidates, you give them each at least half of a vote
     against eachother, that would bring Mono-Add-Plump
     compliance, it seems to me.

     So maybe it would avoid criticism of MDDA.

     But, if used with MDDTR, it would spoil CD.

     You wrote:



         I agree with Chris Benham that mono-add-plump failure
         would be fatal in a public proposal.


     What if you're going to rank X last in your ranking. With all
     the ballots, including yours, X will win. But then you move X
     to 1st place in your ranking, and that makes X lose.

     Would that be ok?

     Michael Ossipoff


         On Thu, Nov 17, 2016 at 2:12 PM, Michael Ossipoff
         <email9648742@gmail.com <mailto:email9648742@gmail.com>>
         wrote:

             I meant to ask: Did you say that MTRI doesn't pass
             FBC? How does FBC failure happen? In return for FBC,
             it should beat MDDTR at vulnerability to burial, and
             not be vulnerable to truncation.

             Anyway, anything you can tell me about the properties
             comparison between MTRI & MDDTR would be helpful.

             MIchael Ossipoff

             On Thu, Nov 17, 2016 at 5:05 PM, Michael Ossipoff
             <email9648742@gmail.com
             <mailto:email9648742@gmail.com>> wrote:

                 For this method, MTRI, the procedural definition
                 is more understandable than the recursive
                 definition (though the recursive definition's
                 brevity could be useful).

                 So this is what I understand MTRI's procedural
                 definition to be:

                 1. Order the candidates by their top-count score,
                 with higher scores at top.

                 2. Switch the lowest pair of adjacent candidates
                 whose lower candidate pair-beats the higher one.

                 Repeat till there are no more pairs to switch.
                 The highest candidate in the order at that time wins.

                 -----------------------------------------------

                 As a CD rank method, this method is a competitor
                 of MDDTR. What are the property differences
                 between MTRI & MDDTR?

                 In particular, how does MTRI compare with MDDTR
                 in regards to protection of a CWs against
                 truncation & burial?

                 Michael Ossipoff


                 On Thu, Nov 17, 2016 at 2:55 PM, Forest Simmons
                 <fsimmons@pcc.edu <mailto:fsimmons@pcc.edu>> wrote:

                     On Thu, Nov 17, 2016 at 10:54 AM, Michael
                     Ossipoff <email9648742@gmail.com
                     <mailto:email9648742@gmail.com>> wrote:

                         But wouldn't Smith//Approval, with
                         approval cutoffs in the rankings, share
                         MDDTR's burial-vullnerability?

                         ...with, additionally, vulnerability to
                         truncation, which MDDTR _doesn't_ have?

                         And Smith//Approval trades MDDTR's FBC
                         for Smith, which I consider an
                         unfavorable trade.


                     Perhaps make truncation the default approval
                     cutoff, but let voters move it higher as an
                     option:

                     45 C
                     30 A>B or A>>B
                     25 B

                     Voting A>>B would be the chicken defense
                     (where sincere is 25 B>A).

                     Voting A>B would be the truncation defense
                     (where sincere is 45 C>B).

                     With this option, MDDA would be an FBC
                     compliant method that is truncation and
                     burial resistant as well as quasi CD compliant.

                     Is there a way to modify MDDA to make it
                     satisfy mono-add-plump?

                     How about incorporating some form of power
                     truncation. When you plump X and reduce the
                     majority victory of Y over Z to a
                     sub-majority, it would revert to a majority
                     if you counted the common truncation of Y and
                     Z against each other as even half a point.

                     Btw, in case you didn't see it, one of my new
                     favorite non-FBC methods is Most Approved
                     Immune(MAI): Elect the most approved immune
                     candidate.

                     This means elect the most approved candidate
                     X that is unbeaten pairwise by the candidate
                     that would win (recursively) if the method
                     were applied to the same ballot set with X
                     disqualified or withdrawn.

                     It is the simplest approval based rank method
                     that confers immunity from second place
                     complaints on its winners.

                     It is quasi CD compliant if voters can
                     specify their approval cutoffs above the
                     truncation level when they want to.

                     A top rank version of this method is fully CD
                     compliant:

                     Elect the Most Top Ranked Immune candidate.
                     (MTRI)

                     In other words elect the most top ranked
                     candidate X that is unbeaten pairwise by the
                     candidate that would win (recursively) if the
                     method were applied to the same ballot set
                     with X disqualified or withdrawn.

                     Forest

On 11/22/2016 9:25 AM, Michael Ossipoff wrote: > With MDDTR, if your plump for X makes hir lose, it's because you added > a ballot. It has nothing whatsoever to do with the fact that the new > ballot plumped for X. > > Your ballot made X lose in spite of the fact that it was a plump for > X, not because it was a plump for X. > > But in IRV, when you make X lose by raising hir from last place to 1st > place, that raising of X was the only thing that you did, and it is > the reason why X lost. That "distinction" is meaningless and completely useless. The idea that adding a ballot is "something you did" that rates a mention is ridiculous. >> [Mike:] Anyway, if IRV is so widely used and successful, then why >> would nonmonotonicity be a problem for MDDTR? > > [Chris:] Because IRV has a traditional and (for many) intuitive algorithm > > [Mike:] So, tradition before merit? Mike, the (quoted) question of yours that I was answering was why "*would* non-monotonicity be a problem for MDDTR?", not why it /should/. > Chris said: > > Just the knowledge that a failure of Mono-add-Plump is theoretically > possible could reduce people's enthusiasm for voting and make it more > likely that those who like to vote by just plumping for their > favourite will stay home. > > [endquote] > > .Then the fact that ranking someone 1st place instead of last place > could make hir lose will likewise make you stay home instead of > showing up and top-ranking your favorite in IRV. > . Monotonicity failures of the Participation-like "Your announced result may be premature, I have only just voted, here is my ballot" type are much more stark and potentially problematic than the "I and everybody else has voted and the result has been announced, but I wish to alter my ballot and have the votes recounted" type. That is because (a) the media and sometimes the major parties are eager for a quick result and usually the winner can be determined without counting all the votes, and (b) because it isn't practical (with a secret ballot) or legal to allow voters to to change their already-cast ballots and demand a recount. Suppose that a simple purely positional method (such as FPP or Approval) has been used and voter P always just plumps for hir favourite. Now suppose that the method changes to IRV. No-one can ever demonstrate to voter P that continuing to vote in the same way can ever cause a worse result for P's favourite than if P had stayed home. That isn't the case with any method (like MDDTR) that fails Mono-add-Plump. So MDDTR's failure of Mono-add-Plump makes for a much stronger stay-at-home incentive than IRV's vulnerability to Push-over strategy, with the result that occasionally a subset of candidate X's supporters could have got a better result for X (than if they'd top-ranked X) by top-ranking some other candidate. > Anyway, we now know that, with the pt/2 provision, MDDA & MDDTR > needn't give up Mono-Add-Plump. ...and evidently MMPO needn't have > the Hitler-with-2-votes problem. > Regarding MDDA, symmetrically completing the ballots only at the bottom and having a moveable approval cutoff fixes its failures of Mono-add-Plump and Plurality and Irrelevant Ballots Independence and in my opinion makes it a good/acceptable method. Chris Benham On 11/22/2016 9:25 AM, Michael Ossipoff wrote: > > > On Sat, Nov 19, 2016 at 12:18 AM, C.Benham <cbenham@adam.com.au > <mailto:cbenham@adam.com.au>> wrote: > > On 11/19/2016 3:14 AM, Michael Ossipoff wrote: >> If the more embarrassing Mono-Raise failure doesn't give IRV any >> acceptance or enactment problem, then why should the less >> embarrassing Mono-Add-Plump failure of MDDTR give MDDTR an >> acceptance or enactment problem? > > Because what you consider more or less "embarrassing" I am sure > isn't in accord with what most people would find unacceptably > ridiculous. > > > You're right. What could be considered ridiculous about making a > candidate lose by raising hir from last choice to 1st choice in your > ranking? > > :^) > > > > >> With MDDTR, if your plump for X makes X lose, it's because you >> added a ballot. It has nothing whatsoever to do with the fact >> that you voted favorably to X. > > That's right. "You" should have found some way to vote for X > without adding a ballot. Unfortunately removing someone else's > ballot when you are in the > polling station is usually impossible or legally risky. > > > Then let me reword it: > > With MDDTR, if your plump for X makes hir lose, it's because you added > a ballot. It has nothing whatsoever to do with the fact that the new > ballot plumped for X. > > Your ballot made X lose in spite of the fact that it was a plump for > X, not because it was a plump for X. > > But in IRV, when you make X lose by raising hir from last place to 1st > place, that raising of X was the only thing that you did, and it is > the reason why X lost. > > >> Anyway, if IRV is so widely used and successful, then why would >> nonmonotonicity be a problem for MDDTR? > > Because IRV has a traditional and (for many) intuitive algorithm > > > So, tradition before merit? > > , and a solid "maximal" set of criterion compliances and MDDTR > doesn't. > > > No doubt everyone has own definition of "solid maximal". > > MDDTR avoids chicken dilemma and meets FBC. > > IRV avoids chicken dilemma but fails FBC. > > IRV was thrown out in Burlington because the CWs's voters have no way > to protect hir from defeat if hir faction is smallest, and neither > does anyone else, short of favorite-burial. > > MDDTR doesn't have that problem. Though MDDTR's protection of a CWs > isn't as good as that of Simmons (unless, with Simmons, that CWs is > being denied approval due to a chicken-dilemma situation), MDDTR still > offers some burial deterrence (helped by voters, including the CWs's > voters, refusing to rank past the CWs), and full truncation-proofness. > > IRV is pretty much unique, in the degree to which no one can do > anything to protect a small-faction CWs. > > I don't oppose IRV, though I don't advocate it either (unless the only > alternative is no change from Plurality). > > As I said in another thread, IRV's long track-record in elections for > national office, is one of 2-party domination. > > > Earlier you attempted to ridicule my observation that MDDTR fails > Irrelevant Ballots Independence by suggesting that might > indirectly motivate a higher > turnout. > > > There's nothing wrong with working to increase turnout. > > Well, just as some might have an interest in promoting that (for > voters who'll ignore the competitive/viable candidates) so as to > wash away > an otherwise likely majority-defeat disqualification so would > opposed forces have an interest in doing the opposite. > > > Sure, some might have incentive to suppress turnout. That that's true > anyway, with any method. Anyway, measures to reduce turnout would be > difficult to justify in Congress, and, in some instances, under > existing law, would be illegal. I don't think that turnout-suppression > with MDDTR would be a problem. > > In any case, the Mono-Add-Plump failure of MDDA & MDDTR is now moot, > because it's avoided by the pt/2 provision. > > > Chris said: > > Just the knowledge that a failure of Mono-add-Plump is theoretically > possible could reduce people's enthusiasm for voting and make it more > likely that those who like to vote by just plumping for their > favourite will stay home. > > [endquote] > > .Then the fact that ranking someone 1st place instead of last place > could make hir lose will likewise make you stay home instead of > showing up and top-ranking your favorite in IRV. > . > Chris said: > > Whereas IRV doesn't just meet mono-add-plump. It also meet Mono-add-Top > > [endquote] > > ...and fails Mono-Raise, and fails FBC in a particularly flagrant way > that won't be unusual.. > >> C: Failing mono-add-plump is as stupid as a quasi-"intelligent" >> device can be, in a pure and starkly obvious way, and with the lamest >> possible excuse. >> >> The algorithm/device decides that X should win, and then receives >> some more ballots that contain nothing whatsoever but the pure and >> simple message: >> "You are right! X should win" and responds with the bizarre >> malfunction "I've changed my mind, Y should win" and offers the >> nonsensical excuse "Hey those >> extra ballots didn't just say that X should win. They also increased >> the total number of ballots!". >> >> >>> C: What (arguably) desirable properties (or criterion compliances) >>> are incompatible with meeting Mono-add-Plump? >>> >>> Mike: FBC, CD, & wv-like strategy are evidently require failing >>> Mono-Add-Plump, or having MMPO's Hitler-with-2-votes problem. >>> >>> With MDDTR, the price of FBC, CD & wv-like strategy is Mono-Add-Plump. >> >> C: There are methods that meet FBC and CD and mono-add-plump. So >> your proposition boils down to saying that it's worth giving up >> compliance with >> mono-add-plump just to gain "wv-like strategy" >> >> . > Sure, I'm more interested in making voting easier, and making > sincerity safer, than in embarrassment criteria. (...and IRV has an at > least equally ridiculous nonmonotonicity). > > I now realize that MDDTR doesn't have wv strategy, though it does have > full truncation-proofness. > > Simmons, MMPO(pt/2), IC,MMPO, and probably other methods meet FBC & > CD, and let voters protect a CWs to varying degrees under different > conditions...something that you have to give up when you choose IRV, > in which a CWs automatically loses if its faction is smallest. > > I'm not saying that the overall IRV package couldn't be ok, if people > understand and accept IRV's problem and won't let it make them > favorite-bury. > > Anyway, we now know that, with the pt/2 provision, MDDA & MDDTR > needn't give up Mono-Add-Plump. ...and evidently MMPO needn't have > the Hitler-with-2-votes problem. > > Michael Ossipoff > > Chris Benham > > > > On 11/19/2016 3:14 AM, Michael Ossipoff wrote: > >> I don't mean that IRV isn't ok. IRV's Mono-Raise failure doesn't >> bother me. >> Neither does MDDTR's Mono-Add-Plump failure. >> >> Voting's purpose is probabilistic anyway. You vote to improve the >> probability of a better outcome. The possible nonmonotonicity of IRV >> & MDDTR doesn't invalidate that. >> >> My point, in asking about when you make someone lose by raising >> hir from last place to 1st place, was just that IRV is popular >> and widely used. It's been used in Australia for a long time, and >> it's used in a fair number of cities in this country. ...and now >> has been adopted by the state of Maine. >> >> ...in spite of its Mono-Raise failure. >> >> If the more embarrassing Mono-Raise failure doesn't give IRV any >> acceptance or enactment problem, then why should the less >> embarrassing Mono-Add-Plump failure of MDDTR give MDDTR an >> acceptance or enactment problem? >> >> There of course have been objections to IRV, some valid, some >> not. But I haven't heard any of the IRV critics in the various >> cities complain about its nonmonotonicity. They object to >> implementation complexity. They invalidly claim voting >> complexity. They invalidly complain because supposedly voting is >> supposed to be by Plurality. They repealed IRV in Burlington >> because of the elimination of a CWv. But none of the complaints >> that I've heard, in cities using it or considering IRV, have been >> about its nonmonotonicity. >> >> Why I say that Mono-Raise failure is more embarrassing: >> >> With MDDTR, if your plump for X makes X lose, it's because you >> added a ballot. It has nothing whatsoever to do with the fact >> that you voted favorably to X. >> >> With IRV, if raising X from bottom to top makes X lose, then X >> lost for no other reason than because you helped hir more. >> >> There are 2 kinds of nonmonotonicity: >> >> Did you make X lose _in spite of_ voting favorably for hir? >> >> or >> >> Did you make X lose _because_ you voted hir more favorably? >> >> Of those 2 kinds of nonmonotonicity the 2nd one is more of an >> embarrassment to the method. There, the method is more directly >> acting oppositely to your action. >> >> Maybe it could be said that the 2nd kind of nonmonotonicity is >> twice as embarrassing to the voting-system. >> >> Anyway, if IRV is so widely used and successful, then why would >> nonmonotonicity be a problem for MDDTR? >> >> I now feel that IRV's (mitigated) problem isn't an unusually high >> price for CD, isn't more than the "going rate" for CD. IRV & its >> derivatives are at the top of my ranking of method-merit for >> electorates who want &/or need ranking. >> >> Michael Ossipoff >> >> >> >> >> >> >> >> On Fri, Nov 18, 2016 at 1:23 AM, Michael Ossipoff >> <email9648742@gmail.com <mailto:email9648742@gmail.com>> wrote: >> >> Forest-- >> >> You wrote: >> >> >> But MAI still fails FBC. >> >> >> Failing both FBC & CD isn't good. >> >> >> So to me the best proposal is ICA with default approval >> cutoff at truncation to help punish burial and truncation >> with an option to raise the cutoff to withstand a CD attack. >> >> >> But buriers or truncators could raise that approval cutoff >> too. Someone could bury X under Z without having to approve >> Z. That loses the deterrence that would exist if that burier >> had to approve Z in order to rank hir over someone, as would >> be so if ranking is counted as approval. >> >> So CD still comes at the cost of a lot less protection >> against burial, or, in ICT's case, trunction too. >> >> But that just means that it isn't _better_ than MDDTR in that >> regard. It doesn't mean that it's worse. >> >> And it doesn't have Mono-Add-Plump failure. >> >> So, the method has CD as MDDTR does, and trades >> truncation-proofness for Mono-Add-Plump. >> >> I value strategy protections more than embarrassment >> criteria. (But I realize that proposal-opponents can use >> embarrassment criteria criticisms, and that proponents aren't >> likely to be able to afford as much media time, to answer the >> criticisms.) >> >> [Replying farther down] : >> >> >> >> Here's my version (slightly different from the original): >> >> Candidate X strongly beats candidate Y iff >> >> the number of ballots on which X is ranked over Y is >> greater than >> >> the number of ballots on which Y is _/*ranked*/_ equal to >> or greater than Y. >> >> [Note Y is not ranked equal to X if Y is not ranked.] >> >> If not all of the candidates are strongly beaten, >> disqualify all of the ones who are. >> >> Elect the most approved qualified candidate. >> >> I think that this method has all of the good properties >> of MDDA with mono-add-plump to boot. >> >> >> I've only had a preliminary look at it, but it seems to me, >> right now, that the separate approval-cutoff that the voter >> can raise from the default spoils protection from burial & >> truncation. >> >> >> You wrote: >> >> We still need to explore MDDA with the half power >> truncation rule, since it would also satisfy >> mono-add-plump if I am not mistaken. >> >> >> Yes, it seems to me that a 1/2 power-truncation would get rid >> of the Mono-Add-Plump failure. If, by not ranking a certain 2 >> candidates, you give them each at least half of a vote >> against eachother, that would bring Mono-Add-Plump >> compliance, it seems to me. >> >> So maybe it would avoid criticism of MDDA. >> >> But, if used with MDDTR, it would spoil CD. >> >> You wrote: >> >> >> >> I agree with Chris Benham that mono-add-plump failure >> would be fatal in a public proposal. >> >> >> What if you're going to rank X last in your ranking. With all >> the ballots, including yours, X will win. But then you move X >> to 1st place in your ranking, and that makes X lose. >> >> Would that be ok? >> >> Michael Ossipoff >> >> >> On Thu, Nov 17, 2016 at 2:12 PM, Michael Ossipoff >> <email9648742@gmail.com <mailto:email9648742@gmail.com>> >> wrote: >> >> I meant to ask: Did you say that MTRI doesn't pass >> FBC? How does FBC failure happen? In return for FBC, >> it should beat MDDTR at vulnerability to burial, and >> not be vulnerable to truncation. >> >> Anyway, anything you can tell me about the properties >> comparison between MTRI & MDDTR would be helpful. >> >> MIchael Ossipoff >> >> On Thu, Nov 17, 2016 at 5:05 PM, Michael Ossipoff >> <email9648742@gmail.com >> <mailto:email9648742@gmail.com>> wrote: >> >> For this method, MTRI, the procedural definition >> is more understandable than the recursive >> definition (though the recursive definition's >> brevity could be useful). >> >> So this is what I understand MTRI's procedural >> definition to be: >> >> 1. Order the candidates by their top-count score, >> with higher scores at top. >> >> 2. Switch the lowest pair of adjacent candidates >> whose lower candidate pair-beats the higher one. >> >> Repeat till there are no more pairs to switch. >> The highest candidate in the order at that time wins. >> >> ----------------------------------------------- >> >> As a CD rank method, this method is a competitor >> of MDDTR. What are the property differences >> between MTRI & MDDTR? >> >> In particular, how does MTRI compare with MDDTR >> in regards to protection of a CWs against >> truncation & burial? >> >> Michael Ossipoff >> >> >> On Thu, Nov 17, 2016 at 2:55 PM, Forest Simmons >> <fsimmons@pcc.edu <mailto:fsimmons@pcc.edu>> wrote: >> >> On Thu, Nov 17, 2016 at 10:54 AM, Michael >> Ossipoff <email9648742@gmail.com >> <mailto:email9648742@gmail.com>> wrote: >> >> But wouldn't Smith//Approval, with >> approval cutoffs in the rankings, share >> MDDTR's burial-vullnerability? >> >> ...with, additionally, vulnerability to >> truncation, which MDDTR _doesn't_ have? >> >> And Smith//Approval trades MDDTR's FBC >> for Smith, which I consider an >> unfavorable trade. >> >> >> Perhaps make truncation the default approval >> cutoff, but let voters move it higher as an >> option: >> >> 45 C >> 30 A>B or A>>B >> 25 B >> >> Voting A>>B would be the chicken defense >> (where sincere is 25 B>A). >> >> Voting A>B would be the truncation defense >> (where sincere is 45 C>B). >> >> With this option, MDDA would be an FBC >> compliant method that is truncation and >> burial resistant as well as quasi CD compliant. >> >> Is there a way to modify MDDA to make it >> satisfy mono-add-plump? >> >> How about incorporating some form of power >> truncation. When you plump X and reduce the >> majority victory of Y over Z to a >> sub-majority, it would revert to a majority >> if you counted the common truncation of Y and >> Z against each other as even half a point. >> >> Btw, in case you didn't see it, one of my new >> favorite non-FBC methods is Most Approved >> Immune(MAI): Elect the most approved immune >> candidate. >> >> This means elect the most approved candidate >> X that is unbeaten pairwise by the candidate >> that would win (recursively) if the method >> were applied to the same ballot set with X >> disqualified or withdrawn. >> >> It is the simplest approval based rank method >> that confers immunity from second place >> complaints on its winners. >> >> It is quasi CD compliant if voters can >> specify their approval cutoffs above the >> truncation level when they want to. >> >> A top rank version of this method is fully CD >> compliant: >> >> Elect the Most Top Ranked Immune candidate. >> (MTRI) >> >> In other words elect the most top ranked >> candidate X that is unbeaten pairwise by the >> candidate that would win (recursively) if the >> method were applied to the same ballot set >> with X disqualified or withdrawn. >> >> Forest >> >> >> >> >> >> >> > > > No virus found in this message. > Checked by AVG - www.avg.com <http://www.avg.com> > Version: 2016.0.7859 / Virus Database: 4664/13452 - Release Date: 11/21/16 >

  De : C.Benham <cbenham@adam.com.au>

Hi Chris, De : C.Benham <cbenham@adam.com.au> À : Michael Ossipoff <email9648742@gmail.com> Cc : EM <election-methods@lists.electorama.com>; Forest Simmons <fsimmons@pcc.edu> Envoyé le : Mardi 22 novembre 2016 10h51 Objet : Re: [EM] Trying to have CD, protect strong top-set, and protect middle candidates too On 11/22/2016 9:25 AM, Michael Ossipoff wrote: >>With MDDTR, if your plump for X makes hir lose, it's because you added a ballot. It has nothing whatsoever to do with the fact that the new ballot plumped for X. >>Your ballot made X lose in spite of the fact that it was a plump for X, not because it was a plump for X. >>But in IRV, when you make X lose by raising hir from last place to 1st place, that raising of X was the only thing that you did, and it is the reason why X lost. > >That "distinction" is meaningless and completely useless.  The idea that adding a ballot is "something you did" that rates a mention is ridiculous. I'm not sure about this specific example but I think this kind of distinction could be a useful defense. For IRV I might argue that a mono-raise failure happens not just from raising the winner but also lowering some other, incidental candidate. The reason mono-raise failures are offensive is that supposedly the voter has done nothing but aid the preexisting winner. But at least in IRV it is not so clear as that. >Regarding MDDA,  symmetrically completing the ballots only at the bottom and having a moveable approval cutoff fixes its failures of Mono-add-Plump >and Plurality and Irrelevant Ballots Independence and in my opinion makes it a good/acceptable method. Hmm, with a movable cutoff MDDA already violates Plurality with three candidates. Do you think symmetric-completion of the bottom can save it? For whatever interest it may be, I calculated the "DNA" for the method you describe and got the exact same 343-digit code as for ICA(explicit). That's the first time I've hit a method I already had... Chris Benham

On 11/23/2016 10:59 AM, Kevin Venzke wrote: > Hmm, with a movable cutoff MDDA already violates Plurality with three > candidates. Do you think symmetric-completion of the bottom can save it? Yes. Something Toby Pereira wrote (9 Nov. 2016) regarding "Irrelevant Ballots" got me thinking. The criterion I defined just talks about ballots that plump for nobody, but there can also be a problem with ballots that only vote nobodies below, say, equal-top. Under MDDA with symmetric completion only at the bottom, adding ballots like that can wash away "majority-defeat" disqualifications and make the result less Condorcet-consistent. This has led me to think of a modification to fix this problem that looks to be too good to be true, but so far I can't see how. *Voters submit rankings with an explicit approval cutoff. (I prefer default placement to be just below candidates ranked below no-one). On the ballots that have been symmetrically completed at the bottom, find the smallest set S of candidate/s that majority-strength pairwise beat all the outside-S candidates. Disqualify the outside-S candidate/s and delete all the ballots that make no distinction among the inside-S candidates. Repeat as many times as possible. If at the end of this process more than one candidate hasn't been disqualified, elect the one of those by normal MDDA (SC).* I am fearful that this might fail FBC and/or mono-raise, but I can't (yet) see how it does. 45: A>B>>C 10: A=B 40: B 05: C 100 ballots. After symmetrically completing at the bottom we get A>B 47.5 - 42.5, A>C 75-25, B>C 95-5. Normal MDDA(SC) disqualifies only C and then elects the most approved candidate, B. My suggested version first disqualifies C and then deletes the 5 C and 10 A=B ballots and then disqualifies B leaving A (the CW) as the winner. What do you think? Chris Benham On 11/23/2016 10:59 AM, Kevin Venzke wrote: > Hi Chris, > > > ------------------------------------------------------------------------ > *De :* C.Benham <cbenham@adam.com.au> > *À :* Michael Ossipoff <email9648742@gmail.com> > *Cc :* EM <election-methods@lists.electorama.com>; Forest Simmons > <fsimmons@pcc.edu> > *Envoyé le :* Mardi 22 novembre 2016 10h51 > *Objet :* Re: [EM] Trying to have CD, protect strong top-set, and > protect middle candidates too > > On 11/22/2016 9:25 AM, Michael Ossipoff wrote: > > >>With MDDTR, if your plump for X makes hir lose, it's because you added a > ballot. It has nothing whatsoever to do with the fact that the new > ballot plumped for X. > >>Your ballot made X lose in spite of the fact that it was a plump for > X, not because it was a plump for X. > >>But in IRV, when you make X lose by raising hir from last place to > 1st place, that raising of X was the only thing that you did, and it > is the reason why X lost. > > > >That "distinction" is meaningless and completely useless. The idea that > adding a ballot is "something you did" that rates a mention is ridiculous. > > I'm not sure about this specific example but I think this kind of > distinction could be a useful defense. For IRV I might argue that a > mono-raise failure happens not just from raising the winner but also > /lowering/ some other, incidental candidate. The reason mono-raise > failures are offensive is that supposedly the voter has done nothing > but aid the preexisting winner. But at least in IRV it is not so clear > as that. > > >Regarding MDDA, symmetrically completing the ballots only at the > bottom and having a moveable approval cutoff fixes its failures of > Mono-add-Plump > >and Plurality and Irrelevant Ballots Independence and in my opinion > makes it a good/acceptable method. > > Hmm, with a movable cutoff MDDA already violates Plurality with three > candidates. Do you think symmetric-completion of the bottom can save it? > > For whatever interest it may be, I calculated the "DNA" for the method > you describe and got the exact same 343-digit code as for > ICA(explicit). That's the first time I've hit a method I already had... > > Chris Benham > > No virus found in this message. > Checked by AVG - www.avg.com <http://www.avg.com> > Version: 2016.0.7924 / Virus Database: 4664/13460 - Release Date: 11/22/16 >

Kevin suggested IC,MMPO, as a method that meets FBC, avoids chicken-dilemma, and has MMPO's (uncertain) kind of protection of a middle-ranked CWs. MMPOsc achieves that too,and the symmetrical completion avoids the Hitler-with-2-votes bad-example. But the symmetrical completion that it needs spoils its truncation-proofness. So an advantage of IC,MMPO over MMPOsc is truncation proofness, because the IC avoids MMPO's bad-example, and so the symmetrical completion isn't needed. Forest's MDDAsc could be used with IC too. IC,MDDAsc would add a sort of Condorcet-Criterion compliance. I guess the symmetrical completion would still be needed, to keep Mono-Add-Plump,but, it doesn't do any harm to MDDA's solid, positive protection of a middle-ranked CWs to whom approval isn't denied.. So that's four related methods: MDDAsc MMPOsc IC,MDDAsc IC,MMPO Some advantages among them: MDDAsc: Protection of a middle-ranked CWs is positive & solid, if approval isn't denied that candidate. MMPOsc: Chicken-dilemma deterrence is automatic. All middle-ranked candidates would receive some (uncertain) protection if they're CWs. But the protection of _any_ middle-ranked CWs is uncertain, and might or might not be there. The necessary symmetrical completion spoils the truncation-proofness that MMPO would otherwise have.. Deterrence of burial and truncation depends on the would-be buriers knowing if the strength of pairwise oppositions favors them, or will result in penalty. It depends largely on whether the candidate under whom they bury the CWs has strong pairwise opposition other than by the CWs. Maybe that threat would depend on the voters of the defending wing, between the median and any possible burying-candidate, purposely leaving hir only weakly pairwise-opposed (other than by the CWs). If there are a number of candidates under whom the CWs could be buried, and who could receive strong pairwise opposition, then it might be necessary to give low opposition (other than by the CWs) to a number of them. Anyway, the protection of a middle-ranked CWs is always uncertain. IC,MDDAsc: Compiance with Improved Condorcet Criterion is added to MDDAsc's properties. IC,MMPO. Same as above. Also, because symmetrical completion isn't needed, due to IC, this method has, as an advantage over MMPOsc, that it's truncation-proof. ------------------------------------------------- MDDAsc & IC,MDDAsc seem to win the comparison because the voter can give full, sold, positive protection to a candidate to whom s/he doesn't deny approval. Chicken dilemma will be relatively uncommon, and so approval won't usually be denied. Michael Ossipoff On Wed, Nov 23, 2016 at 8:09 AM, C.Benham <cbenham@adam.com.au> wrote: > On 11/23/2016 10:59 AM, Kevin Venzke wrote: > > Hmm, with a movable cutoff MDDA already violates Plurality with three > candidates. Do you think symmetric-completion of the bottom can save it? > > > Yes. > > Something Toby Pereira wrote (9 Nov. 2016) regarding "Irrelevant Ballots" > got me thinking. The criterion I defined just talks about ballots > that plump for nobody, but there can also be a problem with ballots that > only vote nobodies below, say, equal-top. > > Under MDDA with symmetric completion only at the bottom, adding ballots > like that can wash away "majority-defeat" > disqualifications and make the result less Condorcet-consistent. > > This has led me to think of a modification to fix this problem that looks > to be too good to be true, but so far I can't see how. > > *Voters submit rankings with an explicit approval cutoff. (I prefer > default placement to be just below candidates ranked below no-one). > > On the ballots that have been symmetrically completed at the bottom, find > the smallest set S of candidate/s that majority-strength pairwise > beat all the outside-S candidates. > > Disqualify the outside-S candidate/s and delete all the ballots that make > no distinction among the inside-S candidates. > > Repeat as many times as possible. If at the end of this process more than > one candidate hasn't been disqualified, elect the > one of those by normal MDDA (SC).* > > I am fearful that this might fail FBC and/or mono-raise, but I can't > (yet) see how it does. > > 45: A>B>>C > 10: A=B > 40: B > 05: C > > 100 ballots. After symmetrically completing at the bottom we get A>B > 47.5 - 42.5, A>C 75-25, B>C 95-5. > > Normal MDDA(SC) disqualifies only C and then elects the most approved > candidate, B. > > My suggested version first disqualifies C and then deletes the 5 C and > 10 A=B ballots and then disqualifies B leaving A (the CW) > as the winner. > > What do you think? > > Chris Benham > > > On 11/23/2016 10:59 AM, Kevin Venzke wrote: > > Hi Chris, > > > ------------------------------ > *De :* C.Benham <cbenham@adam.com.au> <cbenham@adam.com.au> > *À :* Michael Ossipoff <email9648742@gmail.com> <email9648742@gmail.com> > *Cc :* EM <election-methods@lists.electorama.com> > <election-methods@lists.electorama.com>; Forest Simmons <fsimmons@pcc.edu> > <fsimmons@pcc.edu> > *Envoyé le :* Mardi 22 novembre 2016 10h51 > *Objet :* Re: [EM] Trying to have CD, protect strong top-set, and protect > middle candidates too > > On 11/22/2016 9:25 AM, Michael Ossipoff wrote: > > >>With MDDTR, if your plump for X makes hir lose, it's because you added > a ballot. It has nothing whatsoever to do with the fact that the new ballot > plumped for X. > >>Your ballot made X lose in spite of the fact that it was a plump for X, > not because it was a plump for X. > >>But in IRV, when you make X lose by raising hir from last place to 1st > place, that raising of X was the only thing that you did, and it is the > reason why X lost. > > > >That "distinction" is meaningless and completely useless. The idea that > adding a ballot is "something you did" that rates a mention is ridiculous. > > I'm not sure about this specific example but I think this kind of > distinction could be a useful defense. For IRV I might argue that a > mono-raise failure happens not just from raising the winner but also > *lowering* some other, incidental candidate. The reason mono-raise > failures are offensive is that supposedly the voter has done nothing but > aid the preexisting winner. But at least in IRV it is not so clear as > that. > > >Regarding MDDA, symmetrically completing the ballots only at the bottom > and having a moveable approval cutoff fixes its failures of Mono-add-Plump > >and Plurality and Irrelevant Ballots Independence and in my opinion makes > it a good/acceptable method. > > Hmm, with a movable cutoff MDDA already violates Plurality with three > candidates. Do you think symmetric-completion of the bottom can save it? > > For whatever interest it may be, I calculated the "DNA" for the method you > describe and got the exact same 343-digit code as for ICA(explicit). That's > the first time I've hit a method I already had... > > Chris Benham > > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2016.0.7924 / Virus Database: 4664/13460 - Release Date: 11/22/16 > > > > ---- > Election-Methods mailing list - see http://electorama.com/em for list info > >

Sorry to bother you yet again about this comparison, but I just want to say one more thing about it: It occurs to me that I was needlessly worried about a conflict, in MDDAsc, between protecting against chicken-dilemma defection by B's voters, vs protecting B from truncation & burial if s/he is CWs. II realize that, in the standard chicken-dilemma example, C is majority-disqualified, and is the only majority-disqualified candidate. In that 3-candidate example, if B were the larger of {A,B}, and were CWs, then, with the B voters not ranking or approving C, then, if the C voters buried B under A, they'd thereby elect A as the only non-disqualified candidate. (as several people have already pointed out). So, in the chicken-dilemma situation, even if B were the CWs, s/he wouldn't need an approval from A, for deterrence against truncation or burial. The chicken-dilemma exists when people feel pretty sure that it exists. If it looks & feels like a chicken-dilemma situaton, i probably is. It's disconcertingly obvious. And, then, there's no need to worry "What if it might, instead, be a situation in which B needs approval from the A voters?" So my concern about that was needless. It's clear when it's a chicken-dilemma situation, and MDDAsc works fine in that situation. The voter has the option of dealing with the chicken-dilemma situation when it's clear that there is one, and also _fully, solidly, positively_ protecting, from truncation & burial, middle-ranked candidates who need that protection. Michael Ossipoff On Thu, Nov 24, 2016 at 10:27 PM, Michael Ossipoff <email9648742@gmail.com> wrote: > Kevin suggested IC,MMPO, as a method that meets FBC, avoids > chicken-dilemma, and has MMPO's (uncertain) kind of protection of a > middle-ranked CWs. > > MMPOsc achieves that too,and the symmetrical completion avoids the > Hitler-with-2-votes bad-example. But the symmetrical completion that it > needs spoils its truncation-proofness. > > So an advantage of IC,MMPO over MMPOsc is truncation proofness, because > the IC avoids MMPO's bad-example, and so the symmetrical completion isn't > needed. > > Forest's MDDAsc could be used with IC too. IC,MDDAsc would add a sort of > Condorcet-Criterion compliance. I guess the symmetrical completion would > still be needed, to keep Mono-Add-Plump,but, it doesn't do any harm to > MDDA's solid, positive protection of a middle-ranked CWs to whom approval > isn't denied.. > > So that's four related methods: > > MDDAsc > MMPOsc > IC,MDDAsc > IC,MMPO > > Some advantages among them: > > MDDAsc: > > Protection of a middle-ranked CWs is positive & solid, if approval isn't > denied that candidate. > > MMPOsc: > > Chicken-dilemma deterrence is automatic. All middle-ranked candidates > would receive some (uncertain) protection if they're CWs. But the > protection of _any_ middle-ranked CWs is uncertain, and might or might not > be there. > > The necessary symmetrical completion spoils the truncation-proofness that > MMPO would otherwise have.. > > Deterrence of burial and truncation depends on the would-be buriers > knowing if the strength of pairwise oppositions favors them, or will result > in penalty. It depends largely on whether the candidate under whom they > bury the CWs has strong pairwise opposition other than by the CWs. Maybe > that threat would depend on the voters of the defending wing, between the > median and any possible burying-candidate, purposely leaving hir only > weakly pairwise-opposed (other than by the CWs). If there are a number of > candidates under whom the CWs could be buried, and who could receive strong > pairwise opposition, then it might be necessary to give low opposition > (other than by the CWs) to a number of them. > > Anyway, the protection of a middle-ranked CWs is always uncertain. > > IC,MDDAsc: > > Compiance with Improved Condorcet Criterion is added to MDDAsc's > properties. > > IC,MMPO. > > Same as above. Also, because symmetrical completion isn't needed, due to > IC, this method has, as an advantage over MMPOsc, that it's > truncation-proof. > > ------------------------------------------------- > > MDDAsc & IC,MDDAsc seem to win the comparison because the voter can give > full, sold, positive protection to a candidate to whom s/he doesn't deny > approval. Chicken dilemma will be relatively uncommon, and so approval > won't usually be denied. > > Michael Ossipoff > > > > > > On Wed, Nov 23, 2016 at 8:09 AM, C.Benham <cbenham@adam.com.au> wrote: > >> On 11/23/2016 10:59 AM, Kevin Venzke wrote: >> >> Hmm, with a movable cutoff MDDA already violates Plurality with three >> candidates. Do you think symmetric-completion of the bottom can save it? >> >> >> Yes. >> >> Something Toby Pereira wrote (9 Nov. 2016) regarding "Irrelevant >> Ballots" got me thinking. The criterion I defined just talks about ballots >> that plump for nobody, but there can also be a problem with ballots that >> only vote nobodies below, say, equal-top. >> >> Under MDDA with symmetric completion only at the bottom, adding ballots >> like that can wash away "majority-defeat" >> disqualifications and make the result less Condorcet-consistent. >> >> This has led me to think of a modification to fix this problem that looks >> to be too good to be true, but so far I can't see how. >> >> *Voters submit rankings with an explicit approval cutoff. (I prefer >> default placement to be just below candidates ranked below no-one). >> >> On the ballots that have been symmetrically completed at the bottom, find >> the smallest set S of candidate/s that majority-strength pairwise >> beat all the outside-S candidates. >> >> Disqualify the outside-S candidate/s and delete all the ballots that make >> no distinction among the inside-S candidates. >> >> Repeat as many times as possible. If at the end of this process more >> than one candidate hasn't been disqualified, elect the >> one of those by normal MDDA (SC).* >> >> I am fearful that this might fail FBC and/or mono-raise, but I can't >> (yet) see how it does. >> >> 45: A>B>>C >> 10: A=B >> 40: B >> 05: C >> >> 100 ballots. After symmetrically completing at the bottom we get A>B >> 47.5 - 42.5, A>C 75-25, B>C 95-5. >> >> Normal MDDA(SC) disqualifies only C and then elects the most approved >> candidate, B. >> >> My suggested version first disqualifies C and then deletes the 5 C and >> 10 A=B ballots and then disqualifies B leaving A (the CW) >> as the winner. >> >> What do you think? >> >> Chris Benham >> >> >> On 11/23/2016 10:59 AM, Kevin Venzke wrote: >> >> Hi Chris, >> >> >> ------------------------------ >> *De :* C.Benham <cbenham@adam.com.au> <cbenham@adam.com.au> >> *À :* Michael Ossipoff <email9648742@gmail.com> <email9648742@gmail.com> >> *Cc :* EM <election-methods@lists.electorama.com> >> <election-methods@lists.electorama.com>; Forest Simmons >> <fsimmons@pcc.edu> <fsimmons@pcc.edu> >> *Envoyé le :* Mardi 22 novembre 2016 10h51 >> *Objet :* Re: [EM] Trying to have CD, protect strong top-set, and >> protect middle candidates too >> >> On 11/22/2016 9:25 AM, Michael Ossipoff wrote: >> >> >>With MDDTR, if your plump for X makes hir lose, it's because you added >> a ballot. It has nothing whatsoever to do with the fact that the new ballot >> plumped for X. >> >>Your ballot made X lose in spite of the fact that it was a plump for X, >> not because it was a plump for X. >> >>But in IRV, when you make X lose by raising hir from last place to 1st >> place, that raising of X was the only thing that you did, and it is the >> reason why X lost. >> > >> >That "distinction" is meaningless and completely useless. The idea that >> adding a ballot is "something you did" that rates a mention is ridiculous. >> >> I'm not sure about this specific example but I think this kind of >> distinction could be a useful defense. For IRV I might argue that a >> mono-raise failure happens not just from raising the winner but also >> *lowering* some other, incidental candidate. The reason mono-raise >> failures are offensive is that supposedly the voter has done nothing but >> aid the preexisting winner. But at least in IRV it is not so clear as >> that. >> >> >Regarding MDDA, symmetrically completing the ballots only at the bottom >> and having a moveable approval cutoff fixes its failures of Mono-add-Plump >> >and Plurality and Irrelevant Ballots Independence and in my opinion >> makes it a good/acceptable method. >> >> Hmm, with a movable cutoff MDDA already violates Plurality with three >> candidates. Do you think symmetric-completion of the bottom can save it? >> >> For whatever interest it may be, I calculated the "DNA" for the method >> you describe and got the exact same 343-digit code as for ICA(explicit). >> That's the first time I've hit a method I already had... >> >> Chris Benham >> >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 2016.0.7924 / Virus Database: 4664/13460 - Release Date: 11/22/16 >> >> >> >> ---- >> Election-Methods mailing list - see http://electorama.com/em for list >> info >> >> >