[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 :
> Another characteristic feature of the Schulze method is the
> use of winning votes. My understanding is that the history
> behind winning votes is mostly based on strategic voting
> related concerns. Unless use of winning votes is considered
> ideal for sincere votes, this decision means some deviation
> from electing ideal winners wit sincere votes.
> 
> Yet another possible factor that may influence this
> discussion on what the basic idea behind Schulze method (and
> other methods) is is the concept of implicit approval cutoff
> after the ranked candidates. Some criteria and discussion on
> what the ideal winner is do refer to the assumption that
> voters have indicated that they support/approve those
> candidates that they have ranked and do not support
> candidates that they have not ranked. (Depending on the
> ballot type and number of candidates and interpretation that
> could mean truncation or candidates ranked equal last.) This
> interpretation of the votes is thus not purely ranking based
> but includes also additional information. One problem of
> this approach is that if voters behave this way then will
> not express their preferences on the preference between
> those candidates that they do not like, and that could mean
> high level of truncation and bullet voting. Implicit
> approval argumentation usually appears together with
> arguments on why winning votes are natural or how they
> work.
> 
> My understanding of the history of developments behind the
> Schulze method is that in addition to Condorcet
> compatibility one has aimed at summable matrix, 100%
> independence of clones, defence against some strategic
> voting patterns (=> winning votes), deterministic
> decisions (best candidate elected, no lotteries, except when
> exact ties). I don't think the interest to aim at minimum
> number of ballots that must be eliminated (or added) has
> been a key target, at least not the leading one. The
> strategic concerns must have been strong if one considers
> winning votes not to be optimal with sincere votes.

*Who* must have considered winning votes to not be optimal with sincere
votes?

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.

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? Considering that you just complained about the potential 
strategic implications of the WV view of truncation.

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. The main difference between Schulze and RP is a preference
to ignore small defeats over trying to make a ranking by locking larger
defeats.

Kevin Venzke