[EM] Hey guys, look at this...

Tue Feb 21 15:39:42 PST 2023

 I get the feeling that you consider score ballots to be a non-starter in electoral reform. Do you think this the case?
Toby
    On Tuesday, 21 February 2023 at 18:56:52 GMT, Forest Simmons <forest.simmons21 at gmail.com> wrote:  

 Toby,
Good points!
Many of us wish we had the advantages of score ballots.
Score Sorted Margins is one of the best Condorcet methods that shows what you can do with score ballots. Without score ballots or explicit approval cutoffs the best you can do in this vein is implicit approval sorted margins.
How about Borda Sorted Margins? 
Clone dependent.  
Thus the infestation of clone dependent Condorcet completion methods ... Black, Nanson, Kemeny-Young, Baldwin, not to mention all of Quick and Dirty kluges that have been resorted to.
Clone Winner says that if the method winner is replaced by a clone set, the new winner should be from the clone set ... preferably the member of the clone set that would be elected if the method were restricted to the clone set.
Thanks for bringing out these important points!
-Forest

On Tue, Feb 21, 2023, 3:19 AM Toby Pereira <tdp201b at yahoo.co.uk> wrote:

 Well I think a problem with ranking = implicit approval is that a voter might have a preference between two candidates they hate just as much as between two candidates they like, and they would have to implicitly approve one of these candidates to make the distinction.
I sometimes think that Condorcet with cardinal ballots would work better. You have scores or grades, but don't use the values themselves for anything, just the ordinal positions. This way you can easily equal rank at the top, bottom, or somewhere in the middle, not just at the end by not ranking the candidates you hate.
I also think it could alleviate some of the problems of burial. Burial isn't necessarily just a problem because of deliberate strategising. If there are two main candidates, one that a voter likes (A), and one that a voter dislikes (B), and couple of relative unknowns (C and D), there seems to be a prevailing view that because A and B are the "strongest" candidates, an honest vote would be something like A>B>C>D, people would only bottom rank B as some sort of burial strategy, which must be overcome by the method. But I don't think that's the case. Most voters would probably bottom rank B anyway in this case, and do something like A>C>D>B or just A>C>B. But with cardinal ballots, they would be more likely to simply give a zero score to all the candidates they dislike and non-entities. B would therefore be less likely to be buried under other candidates.
As for the clone thing, I'm not entirely sure what all the different clone definitions are - e.g. I can't easily find a definition of clone winner.
Toby
    On Monday, 20 February 2023 at 19:22:13 GMT, Forest Simmons <forest.simmons21 at gmail.com> wrote:  

 Toby,

Thanks for you thoughtful critique!
Do you think  it's worth the extra verbiage of conflating truncation and bottom rank?
Many times I have conflated them by saying D has "Ballot Bottom Status" because it outranks no candidate.
But imho leaving the distinction intact is both simpler and totally harmless ... it just gives voters an optional lever to pull if they want to.
Also in the present context it confers ISDA compliance. Elimination of Smith dominated candidates does not change the unranked/abstention count of any remaining candidate, but it may well change the Ballot Bottom Status of some of them.
One can take the point of view thatthe ordinal information is the same on both ballots, but the implicit approval is different.  The truncation boundary can be considered as an implicit approval cutoff ... awkward, but better than anything possible under strict Universal Domain constraints.
With regard to clone dependence ... doesn't it satisfy clone-winner, unlike any of the other suggestions in this thread?

Doesn't Approval, including implicit approval, satisfy a version of clone independence? It does under the assumption that true clones are not interrupted by the virtual approval cutoff candidate (truncation boundary in this case) any more than they are by other candidates.
Our defeat strength gauge is winning pairwise support plus losing truncations.
If you replace the defeat winner with a precise clone set ... each member of the clone set will have the same pairwise support against the loser, so they will be tied for the strongest victory over the same loser. In practice, the clone sets are not precise ... but if they were the tie could easily be broken by applying the method recursively to the tied set ... if no simpler method existed ... like choosing the tied candidate with the greatest equal-first count ... another helpful expedient that exists outside of the strict UD rules.
Another option that makes hardly any difference to the method except to make its description more wordy, is to gauge defeat strength by winner implicit approval plus loser implicit disapproval.
Implicit disapproval is already the number of truncations. 
And every ballot that pairwise supports the winner over the loser already contributes to the winner's implicit approval .... so the implicit approval count will be an increase over the pairwise support.
But is it worth the extra wordiness required ... talking about implicit approval? We studiously avoided that talk by using "winning votes" a familiar notion in the context of defeat strength as a proxy for implicit approval.
Ultimately, if it turns out to make any difference, we should go with the one that works best .... even if it takes more verbiage.
-Forest

On Mon, Feb 20, 2023, 3:14 AM Toby Pereira <tdp201b at yahoo.co.uk> wrote:

 One thing I'm uncomfortable with is the notion of "unranked" candidates. If there are 4 candidates - A, B, C and D - and one ballot has A>B>C>D and another just A>B>C, they should be treated as the same. Unranked is just (possibly joint) last and I don't see it as having special status.
Toby
    On Monday, 20 February 2023 at 01:28:18 GMT, Forest Simmons <forest.simmons21 at gmail.com> wrote:  

 I have learned a lot from the "hay guys" thread that spontaneously upgraded into this "hey guys" thread.
Colin Champion made some very helpful points and pointers about the psychology of what we are involved in. Many similar practical considerations contributed by all participants.
Several suggestions have been made about how to complete this sentence:
"Lacking a candidate that defeats every other candidate in pairwise head-to-head comparisons, elect the candidate that ..."
I can live with most of those suggestions ... which is neither here nor there in the grand scheme of things ... but I hope haven't offended anybody or discouraged anybody's contributions to these explorations.
Several people have said, "Why not just ...?"
And I thought, "Why didn't I think of that?"
The most promising idea I am currently thinking along these lines goes like this:
Elect the pairwise undefeated champion ... or lacking such a champion, elect the winner of the strongest pairwise defeat ... meaning the pairwise contest with the greatest sum of winner approval and loser disapproval ... winner approval measured by winning votes ... the number of ballots on which the winner outranks the loser... loser disapproval measured by loser abstentions ... the number of ballots on which the pairwise loser is unranked.
So winning votes plus loser abstentions is my proposal for defeat strength ... not to be used in Rsnked Pairs ... but just in the first and strongest step of RP ... and then only in the absence of a Condorcet Winner.
For now it's just an idea needing an experimental shake down beyond my meager manual tests.
But who knows?
-Forest 
On Sun, Feb 19, 2023, 10:47 AM Colin Champion <colin.champion at routemaster.app> wrote:

  I asked Kristofer whether Condorcet+FPTP complied with the Condorcet Loser criterion. He replied "probably not" with a sketch proof, and then gave the following example.

 <quote>
 [preliminary election]

 40: L>C>R 
 42: R>C>L 
 10: C>L>R 

 R is the Condorcet loser and Plurality winner. (L is the IRV winner.) 

 Now clone C, the CW: 

 40: L>Ca>Cb>Cc>R 
 42: R>Cb>Cc>Ca>L 
 10: Cc>Ca>Cb>L>R 

 There's no CW, so Plurality elects R, the Condorcet loser. (Incidentally, R ties for first in minmax.) 

 Seems OK. Verified with https://web.archive.org/web/20220403135047/http://www.cs.angelo.edu/~rlegrand/rbvote/calc.html. 
 </quote>

 I'd wondered whether Robert didn't have any intellectual commitent to the criterion, but had used it in argument against IRV and therefore found his options limited. 

 CJC

 On 19/02/2023 17:31, Kristofer Munsterhjelm wrote:

On 2/19/23 16:36, Colin Champion wrote: 

"Politicians and the voting public would not accept anything more complicated than X" is my own favourite line of argument - but I substitute my own value for X(minimax). I know that my judgement is coloured by my preferences. There's a surprising degree of dissent over which methods are simpler than which, and where the boundary should be drawn. People who deal directly with politicians and the voting public can no doubt get closer to the truth than people whose interest is predominantly theoretical, but I wish there was an authoritative and objective source of information. If only some behavioural psychologist was funded to investigate the question... 

 To be finicky, the issue isn't exactly one of simplicity but rather one of psychological acceptability, which includes the notions of whether a method "makes sense" to the average onlooker, and whether it is seen as conferring legitimacy on its winner rather than being an unmotivated piece of jiggery pokery. 

 Notwithstanding all this... you and Robert may well be right. 

 FWIW, I suspect the complexity people are willing to accept depends on their trust in the political process in general. For instance, some local New Zealand elections use Meek's method, which is complex however you put it.[1] And I wouldn't be prepared to explain the pretty messy greedy algorithm used to allocate party list top-up seats here (in Norway), but people seem to accept it.[2] 

 I don't think Robert could use minmax because the criterion he's using is "if more people prefer X to Y than vice versa, then Y is not elected". That seems to imply at least Condorcet loser. I'm not sure, though -- if you're particularly critical, you could even say it implies Smith, but I don't think Robert had that in mind. 

 -km 

 [1] I wonder what the legal language for *that* is... it's basically impossible to do by hand. 
 [2] IMHO, biproportional apportionment is *much* simpler. I suspect what's keeping it from being changed is mostl inertia. 

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