[EM] Comparing CW with "write-in pairwise" CW

[Kevin Venzke]

Hi Robert,




----- Mail original -----
> De : robert bristow-johnson <rbj at audioimagination.com>
> À : election-methods at lists.electorama.com
> Cc : 
> Envoyé le : Lundi 28 octobre 2013 20h17
> Objet : Re: [EM] Comparing CW with "write-in pairwise" CW
> 
> On 10/27/13 11:26 AM, Kevin Venzke wrote:
>>  Recently I wrote about the concept of allowing write-in votes in individual 
> pairwise contests. I prefer the "approval" formulation which depicts 
> each pairwise contest as an Approval race. In effect the meaning is that an 
> ordinary pairwise win of X over Y is replaced by a tie, when more voters prefer 
> some other candidate Z to both X and Y, than the number of voters who prefer X 
> to Y.
>> 
>>  The motivation behind this concept is to try to come up with a pairwise 
> relationship with some intuitive relevance to the election as a whole. If 
> candidate X has no possibility of winning the election, then I want to recognize 
> as "noise" his pairwise wins, because they don't (or should not!) 
> aid him, and any effect they do have will be arbitrary.
> 
> again, i just don't see the need. if X has no possibility of winning 
> the election, he/she will lose to at least one (likely more) other 
> candidate in a pairwise comparison.
> 

Yes, of course he will. But some methods can elect him anyway, or allow his presence to spoil the outcome, which is the more important thing. I want to minimize spoiled elections.

The purpose isn't a method or a criterion, but the approach to analyzing the ballots. The methods and the criteria mostly already exist.


>
> i know this doesn't fit with your "approval" formulation, but i 
> still 
> have trouble connecting "approval" to Condorcet since the ballots and 
> marking of the ballot are different.  truly Approval (using the Approval 
> ballot) requires less information from the voter than a Ranked ballot.  
> (and, in my opinion, requires more voting tactics from savvy voters than 
> a ranked ballot which is why i don't like Approval for political 
> elections.  i could maybe see it work for "non-partisan" judicial or 
> commissioner elections.)
> 

You might remember from my first message that I initially proposed using FPP rather than Approval. I think many methods could provide a useful result. What I need to identify is: Who likes which candidates better than both of the two in the contest?

If it helps, don't think of it as Approval. Picture another (three-dimensional) pairwise matrix which notes the number of voters preferring some X over both of some Y and Z. It just happens to be the case that Approval (with imposed cutoffs) gets you here.

> 
>>  Furthermore, there should be no shame in being indecisive, considering that 
> Condorcet is often indecisive as well.
> 
> how often, really, is Condorcet indecisive in a real election?
>

I don't know about a real election, but if you just randomly generate scenarios, Condorcet is frequently indecisive. That's what I meant.

Kevin Venzke