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

[Colin Champion]

"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.

CJC


On 18/02/2023 17:53, Bob Richard (lists) wrote:
> Colin makes one argument for learning to live with the plurality 
> winner when there is no Condorcet winner. But it is only part of the 
> reason. Even if the social choice theorists could agree among 
> themselves on one best (or good enough) solution to the riddle of 
> cycles, politicians and the voting public would still not accept 
> anything more complicated than Robert's draft bill, or -- possibly -- 
> "choose the IRV winner when there is no Condorcet winner." (The latter 
> only because IRV is already a somewhat familiar procedure.) The fact 
> that the theorists cancel each other out is only part of this situation.
>
> Robert said earlier that there is a "political problem that *_might_* 
> eclipse the technical problem" (emphasis added). I would say instead 
> that the political problem absolutely eclipses the technical problem.
>
> --Bob Richard
>
> ------ Original Message ------
> From "Colin Champion" <colin.champion at routemaster.app 
> <mailto:colin.champion at routemaster.app>>
> To election-methods at lists.electorama.com 
> <mailto:election-methods at lists.electorama.com>
> Date 2/18/2023 1:42:36 AM
> Subject Re: [EM] Hay guys, look at this...
>
>> I think Robert was wise to propse Condorcet+FPTP. It's the Judgement 
>> of Solomon, allowing him to step aside from endless debates about 
>> which Condorcet method is best.
>>    I don't agree with his reasoning "If a simple majority of voters 
>> mark their ballots preferring Candidate A over Candidate B... Why 
>> should B be elected?" This is the argument of the Condorcet Loser 
>> Criterion, which implicitly assumes that a decision can be determined 
>> purely by the signums of the margins, ignoring their amplitudes. 
>> Minimax violates Condorcet Loser and I'm not the only person to 
>> support it.
>>    But then I don't favour Kristofer's proposal either. My evaluation 
>> suggests that burial is a particular threat for Condorcet methods, 
>> and that in its presence their accuracies are: minimax 64%, 
>> condorcet+fptp 59%, copeland,fptp 48%. [Usual disclaimers apply.]
>>
>> [I would say a word in favour of SPE with an FPTP preranking. This is 
>> a symmetrisation of the method of Llull's De Arte Eleccionis of 1299, 
>> so it's essentially the oldest Condorcet method in existence which 
>> isn't vitiated by indecisiveness. Its virtue lies in its linear-time 
>> countability, which is only a factor if counting is manual and there 
>> is a risk of a sizeable number of candidates standing. SPE is about 
>> as resistant to burial as is minimax.]
>>
>> Wiser judgements than Solomon's are imaginable. If there was a an 
>> expert consensus that among those methods simple enough to gain the 
>> approval of voters and legislators, XYZ was best, then Robert would 
>> probably listen; but the onus is on experts to build a consensus, not 
>> on advocates to take sides.
>>
>> CJC
>>
>>
>> On 18/02/2023 06:05, Forest Simmons wrote:
>>> Let me rephrase the question ... suppose that there were only three 
>>> candidates and you already knew that they were in a rock paper 
>>> scissors pairwise preference cycle.
>>>
>>> How would you decide which one to vote for if you could only vote 
>>> for one?
>>>
>>> That's the one you should make your first choice on an RCV ballot if 
>>> the cycle breaker is FPTP as you have been suggesting.
>>>
>>> That decision is at least as difficult as the approval decision 
>>> would be, because under approval strategy you should approve that 
>>> candidate X (the one you would vote for if you had only one vote) 
>>> AND also approve your favorite if X was not already your favorite.
>>>
>>> These are the same candidates that you would naturally rank on an 
>>> RCV ballot ... leaving the 3rd choice unranked ... the one that is 
>>> neither your favorite nor your compromise.
>>>
>>> If you mis-triangulate the compromise in an FPTP election ... too 
>>> bad: you wasted your vote. But the approval ballot also counts 
>>> towards everybody you like better than your compromise, including 
>>> your favorite.
>>>
>>> That's why Approval is often proposed as a Condorcet completion 
>>> method in the absence of a runoff.
>>>
>>> Implicit approval takes advantage of the natural strategy of 
>>> truncating the candidates you don't like, while ranking your 
>>> preferred of the two front runners AND anybody you liked better ... 
>>> including your favorite ... whether or not it was a frontrunner.
>>>
>>> Yes, the cycle is already there ... but it cannot split the votes 
>>> unless the method allows vote splitting by not having any contingent 
>>> backup vote. Approval has the simplest backup vote capability ... 
>>> any other method requires some kind of runoff/elimination step to 
>>> ameliorate the potential vote split.
>>>
>>> Example ballot profile:
>>>
>>> 40 A>B (Sincere is A>C)
>>> 35 B>C
>>> 25 C>A
>>>
>>> Under Plurality A wins.
>>>
>>> The Implicit Approval (fewest truncations) winner is B with only 25 
>>> truncations, compared with 35 A truncations and 40 C truncations.
>>>
>>> This is a typical kind of ballot profile resulting from the burial 
>>> by the largest faction ... of the sincere Condorcet Winner (C in 
>>> this example).
>>>
>>> If the C supporters wanted to protect C, they could have truncated A:
>>>
>>> 25 C instead of 25 C>A.
>>>
>>> This would not change the Plurality winner, but reinforces the 
>>> Implicit Approval winner, which gives the sincere CW a defense 
>>> against burial by punishing the burying faction ... electing their 
>>> sincere last choice instead of their sincere second choice.
>>>
>>> With this defensive truncation B still has the fewest truncations 
>>> 25, but now the burial perpetrator A has way more truncations (60) 
>>> than either of the others ... no chance of success in their burial 
>>> gambit.
>>>
>>> Electing the Plurality choice (lacking a ballot CW) rewards the 
>>> burial perpetrator in this example .... so it encourages candidates 
>>> with large first place support to bury the sincere CW.
>>>
>>> This example is typical in this respect ... the insincere  burial 
>>> (of sincere CW) gambit is most tempting to the faction with the 
>>> greatest first place support.
>>>
>>> On the other hand it is not tempting to bury the CW when lacking a 
>>> CW the implicit approval candidate is elected ... because this 
>>> burial gambit will almost certainly fail if not outright backfire.
>>>
>>> It seems to me that anybody who understands why Approval is superior 
>>> to FPTP Plurality as an election method ... such a person should be 
>>> able to see how Approval is a better fall back alternative than 
>>> Plurality (absent a CW) .... an appreciable positive difference at 
>>> no extra cost.
>>>
>>> The little Dutch boy was right to put his finger in the dike ... a 
>>> stitch in time is in deed worth nine.
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> On Fri, Feb 17, 2023, 7:07 PM robert bristow-johnson < 
>>> rbj at audioimagination.com <mailto:rbj at audioimagination.com>> wrote:
>>>
>>>
>>>
>>>     > On 02/17/2023 9:44 PM EST Forest Simmons
>>>     <forest.simmons21 at gmail.com <mailto:forest.simmons21 at gmail.com>>
>>>     wrote:
>>>     >
>>>     >
>>>     > Suppose the whole election was to choose one of the three
>>>     candidates ... no noncycle members were in the election at all.
>>>     >
>>>     > Would you recommend FPTP Plurality over Approval?
>>>     >
>>>     >
>>>
>>>     I dunno.  I would recommend Condorcet RCV and, only in the
>>>     super-rare case of a cycle, I would recommend plurality of
>>>     first-choice votes because it's no worse than we already have
>>>     now with FPTP and it's simple to explain to voters why that one
>>>     candidate (the one with more first-choice votes than anyone
>>>     else) is, in some sense, uniquely more preferred by the
>>>     electorate over any other candidate.
>>>
>>>     In a competitive 3-way race, I dunno if Approval would be better
>>>     than FPTP.  I *do* know, if it were Approval, that I would have
>>>     a tactical decision to make regarding my second-favorite candidate.
>>>
>>>     But with RCV, I would have no tactical decision to make.  I
>>>     would know immediately what I would do with my second-fav.
>>>
>>>     --
>>>
>>>     r b-j . _ . _ . _ . _ rbj at audioimagination.com
>>>     <mailto:rbj at audioimagination.com>
>>>
>>>     "Imagination is more important than knowledge."
>>>
>>>     .
>>>     .
>>>     .
>>>
>>>
>>> ----
>>> Election-Methods mailing list - see
>>> https://electorama.com/em  for list info
>>
>
> ----
> Election-Methods mailing list - see https://electorama.com/em for list info

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