[EM] Re: Can we come to consensus? this way?

[Araucaria Araucana]

Abd ulRahman Lomax <abd <at> lomaxdesign.com> writes:
> Not permitting truncation would involve considering ballots as 
> spoiled which are not complete, I think I remember reading that this 
> is actually done in some countries. Personally, I find it just as 
> offensive as spoiling ballots because the voter marked too many 
> candidates.... Definitely, truncation should be allowed, and should 
> have a simple and rational meaning.
> 
> There are two possible meanings: truncation on a ranked ballot means 
> that the voter ranks the candidate below all ranked candidates, and 
> equally with all other unranked candidates. If it is an Approval 
> method, an unmarked candidate would similarly be considered not approved.
> 
> The other meaning possible would be that truncation is an abstention 
> in every pairwise consideration of the unranked candidate. The 
> consequences and implications of this are, however, problematic, and 
> I think voters would not expect this. Presently, not marking a 
> candidate is effectively a vote against that candidate (as long as 
> the voter votes for at least one). Turning that into an abstention 
> would be confusing.

Hi Abd,

I agree that truncation should have the same effect as equal ranking.  After
all, if we are interpreting a ranked ballot in pairwise fashion (which places
no importance on where the ranking occurs but only on the relative ranking),
this is the only possible consistent interpretation.  But what is the effect of
equal ranking?

Is equal ranking is the equivalent of saying "I have no opinion in this
contest"?  Or does it mean "I don't want my vote to hurt either candidate"?
Why not both?

In other words, should pairwise equal-ranked votes be counted (in the
equal-ranked pairwise contest) at all?  The other ordered preferences would
still be counted, of course.

Dave's contention is that in an A-B contest, 2 A=B ballots should be counted as
one A>B ballot and one B>A ballot -- that is, a half-vote for + a half-vote
against.  I disagree.
 
Two opposing ballots may cancel each other's effect, but they each express 
ranked preferences in the pairwise contest and should contribute to its
importance (e.g. in a WV-based Condorcet completion method).  Should two ER
ballots similarly increase the weight of that contest?  In a WV method, that
could have adverse effects -- an A=B ballot could contribute to the loss of
both candidates.

Your final statement about not marking a candidate is confusing.  If ER votes
are *not* counted pairwise (as I contend), that would imply that the non-marked
candidate receives a vote-against from every marked candidate, but no votes,
either for or against, from any other non-marked candidate.  I think this is
the least confusing interpretation for the voter.

Under Dave's ER method (pairwise 1/2 for & 1/2 against), *each*
non-marked candidate would receive a half-vote for and a half-vote against
in *every* non-marked pairwise contest.

I'm sorry if I appear to be arguing against you.  Perhaps we are both arguing
the same side of the issue, and you were simply trying to indicate these same
problems to Dave?

Q