[EM] Fwd: (3) MJ -- The easiest method to 'tolerate'

[C.Benham]

3: A
20: A>B
25: B>A
3: B
20: C>B
29: C

C > B  49-48,   C > A 49-48,   B > A 48-23.

Top Ratings scores:   C 49,   B 28,   A 23

Approval scores:      B 68,   C 49,   A 48.

On 9/7/2016 7:09 AM, Jameson Quinn wrote:
> IBIFA elects C. U/P elects B. It's clear to me that B is better. The 3 
> A-only voters are likely attempting a chicken strategy.

C: C is the clearly voted Condorcet winner and by far the most top-rated 
candidate. The suggestion that "B is better" because of
some guess that 3 truncators are "likely" attempting some strategy is 
absurd.

The best we can reasonably do about chicken strategy is just prevent (or 
reduce the likelihood of) it from succeeding. If the 3 A voters' were 
attempting a
"chicken" (defection) strategy against B, then  electing C means it failed.

BTW, if we weaken all the candidates by 3 plumping votes each, thus:

20: A>B
25: B>A
20: C>B
26: C

then the U/P winner would change from B to C.

Chris Benham



On 9/7/2016 7:09 AM, Jameson Quinn wrote:
>
>
> 2016-09-06 16:07 GMT-04:00 C.Benham <cbenham at adam.com.au 
> <mailto:cbenham at adam.com.au>>:
>
>     On 9/7/2016 1:21 AM, Jameson Quinn wrote:
>>
>>     40: D>...>A,B
>>     35: A>B>D
>>     25: B>...>A,D
>
>     ...
>     But then IBIFA elects B.
>
>
> You're right. So, let's find a situation where they actually differ:
>
>> 5: C>B>A,D
>> 5: C>A>B,D
>> 30: D>...>A,B,C
>> 35: A>B>D,C
>> 25: B>...>A,D,C
> In this scenario, IBIFA elects A, and U/P (my new name for DA, as I 
> stated separately) elects B. I'd still argue that B is the right 
> answer... though I think this whole scenario (and any other I can 
> think of where the two systems differ) is getting pretty implausible, 
> so it's hardly worth arguing.
>
>     No candidate X's Top-Rating score is higher than any candidate Y's
>     approval (i.e. above-bottom rating) score on ballots that don't
>     top-rate X, so
>     IBIFA elects the most approved candidate, B.
>
>>     Obviously, one could tweak these numbers to try to make one or
>>     the other system look better or worse.
>
>     C: Well then I am very curious to see any example where IBIFA 
>     "looks worse" than DA.
>
>
> In your format:
> 3: A
> 20: A>B
> 25: B>A
> 3: B
> 20: C>B
> 29: C
>
> IBIFA elects C. U/P elects B. It's clear to me that B is better. The 3 
> A-only voters are likely attempting a chicken strategy.
>
> This is an artificial scenario designed to make IBIFA look bad. You 
> could do the same to make it look good. I don't think this proves 
> anything besides the fact that IBIFA is not strictly dominant over U/P.
>
>
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