[EM] (3) Best Single-Winner Method

[Ted Stern]

Chris, your point about pushover strategy is a good one.  I was making the
suggestion in an effort to persuade Steve.

Another example which demonstrates problems with MJ is the following:

101: A > B > C > D > E > F > G
101: B > A = C > D > E > F > G
101: C > B = D > A = E > F > G
050: D > C = E > B = F > A = G
099: E > D = F > C = G > B > A
099: F > E = G > D > C > B > A
099: G > F > E > D > C > B > A

which is taken from
https://en.wikipedia.org/wiki/Majority_judgment#Outcome_in_political_environments
.
Majority Judgment selects B while Condorcet (or MCA/Bucklin) selects C, who
seems to be minimizing variance.

Smith//Relevant-Ratings is an interesting method (essentially what Chris
was suggesting earlier).  It seems to be able to handle several burial
attack strategies successfully.

On Tue, Jun 18, 2019 at 8:26 AM C.Benham <cbenham at adam.com.au> wrote:

> I was going to type simply "Good question."
>
> One of the major justifications MJ has is that it  (like Relevant Ratings
> and IBIFA and Bucklin and Approval)
> meets the Favorite Betrayal Criterion (aka FBC) which isn't compatible
> with Condorcet.
>
> In other words, MJ's  (main) excuse for failing Condorcet is that it meets
> FBC.
>
> But when you add a 2-candidate runoff you always have a possible Push-over
> incentive and so no
> compliance with FBC.
>
> And so the whole thing becomes a weird method that meets Condorcet but
> probably fails Smith.
>
> Chris Benham
>
> On 18/06/2019 2:54 pm, Ted Stern wrote:
>
>
>
> On Mon, Jun 17, 2019, 18:51 robert bristow-johnson <
> rbj at audioimagination.com> wrote:
>
>>
>>
>> ---------------------------- Original Message ----------------------------
>> Subject: Re: [EM] (3) Best Single-Winner Method
>> From: "Ted Stern" <dodecatheon at gmail.com>
>> Date: Mon, June 17, 2019 5:24 pm
>> To: "steve bosworth" <stevebosworth at hotmail.com>
>> Cc: "election-methods at lists.electorama.com" <
>> election-methods at lists.electorama.com>
>> --------------------------------------------------------------------------
>>
>> > I would certainly favor Majority Judgment over many other options, if
>> there
>> > were no other choice, though I'd prefer if it included a runoff against
>> the
>> > Condorcet Winner if one exists.
>>
>>
>> I know that i am just stuck in Condorcet land and I haven't completely
>> groked MJ (because i don't like the ballot), but can you guys help me
>> understand how **any** candidate beats the Condorcet Winner in a runoff?
>>
>
> Voters are not rational. Also, in a runoff, they are not necessarily the
> same voters.
>
> If you have an election method and subject that winner of that method to
>> the CW (whom must have been chosen from ranked-ballot results) in a runoff,
>> does not always the CW win?  If so, then why not just elect the CW?
>>
> Indeed, that would be the case. But I think voters may not realize the
> ramifications of their selections in early use of any new method, so an
> option to reconsider might be beneficial.
>
>>
>> --
>>
>> r b-j                         rbj at audioimagination.com
>>
>> "Imagination is more important than knowledge."
>>
>>
>>
>>
>>
>>
>>
>>
>
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