[EM] Meta-criteria 6 of 9: Heuristics. #1, simplicity

[Kevin Venzke]

Hi Juho,

--- En date de : Ven 7.5.10, Juho <juho4880 at yahoo.co.uk> a écrit :
> > *Who* must have considered winning votes to not be
> optimal with sincere
> > votes?
> 
> I don't really know what others have thought. My first
> approach when I first time thought about pairwise comparison
> based methods was that margins would be a natural and simple
> way to measure preference strengths, and I needed an
> explanation to why one would use wining votes. The
> argumentation that I found was related to strategic voting.
>
> > Never mind that you noticed above that WV advocates
> tend to have a
> > different conception of truncation. (Though I wouldn't
> call it
> > disapproval; disapproval is likely, but the point is
> abstention.)
> > 
> > The arguments I remember are about majorities and
> sincere CWs more than
> > about fixing strategic incentives for its own sake.
> 
> There have been arguments that the reason why margins is
> not good is its strategic vulnerabilities when compared to
> winning votes. (This means that winning votes have been
> considered to be better because of strategy related reasons.
> But this doesn't say anything on if someone finds winning
> votes to be ideal with sincere votes.)

And it doesn't say anything on whether someone finds margins to be ideal
with sincere votes.

What *does* mean that WV is considered to be better with sincere votes
is the perspective that when voters truncate they mean to abstain, and
not lend weight to the ignored contests.

> > FPP has strategic problems beyond those found in
> IRV... We don't conclude
> > from this that FPP is better with sincere votes. We
> don't take arguments
> > about FPP's strategic problems as an admission that
> "otherwise" (???) FPP
> > was just fine.
> > 
> > Why couldn't I say that the point of *margins* is to
> minimize a strategic
> > incentive?
> 
> There are cases where margins are less vulnerable to
> strategic voting than winning votes but I don't recall
> anyone saying that margins would have been designed with
> this in mind.

I'm talking about truncation here, and the way margins makes it useless.

My point is more that I don't know of any coherent explanation of why
margins is "ideal" with sincere votes, and WV is not. But that explanation
must be out there if the only problem WV advocates have with margins is
its strategic incentives. There must be some 10+-year-old posts from WV
advocates unhappy that they can't just use margins.

> > Considering that you just complained about the
> potential
> > strategic implications of the WV view of truncation.
> 
> I mentioned at least the possibility of message "truncation
> = approval" possibly leading to shorter than fully ranked
> votes.
> 
> > Schulze and WV are only not focused on minimizing the
> number of
> > "eliminated" ballots in the narrow sense that you pick
> out to support
> > margins. Practically the whole point of WV is to be
> able to ignore the
> > smallest number of preferences that were actually
> specified, rather than
> > imagined.
> 
> With 100 voters opinion 40-30 means that there are 30
> no-opinions or equal opinions. Margins seems to assume that
> the (from 0 to 30) no-opinions are either equal opinions or
> 50%-50% in both directions. One could also assume that every
> truncated vote and vote that contains equal rankings is
> intentionally created by the voter and therefore the voter
> intentionally wants these candidates to be considered equal.
> Winning votes seems to assume that no-opinion and equal
> opinion correspond to voting against the pairwise winner
> since 40-30 and 40-0 have the same meaning.

That is ridiculous. What can "correspond" mean when adding votes against
the pairwise winner can make him the pairwise loser?

I guess what you mean to point out is that WV actually does ignore a
type of preference actually expressed. Fair enough, but it doesn't matter
to my point, which is just that WV actually does have logic that has
a resemblance to - and is as completely arbitrary on a purely aesthetic
level as - the principle of adding/removing as few ballots as necessary
to create a CW.

Kevin Venzke