[EM] Defeat strength, Winning Votes vs. Margins, what to do with equally-ranks on ballot?

[Carl Schroedl]

Good question Robert!

Does anyone know of a publication that addresses this topic? On the site
that Canadian MP Ron McKinnon published to promote Ranked Pairs, it appears
the approach is to add voters' indifferent votes to both candidates when
computing winning votes.

The “majority vote” is the number of votes in which the given majority
> candidate is more-preferred-than the given minority candidate plus the
> no-preference value. The “minority vote” is the number of votes in which
> the minority-candidate is more-preferred-than the given majority candidate
> plus the no-preference value.


https://condorcet.ca/see-how-it-works/how-it-works/
(Click "Ranking the Pairs", then click "Notes")

While I have ideas about the reasoning for the approach, I don't know for
certain. I'll email him about it. MP's tend to be busy, so it may take a
while to get a response. To speed things up, does anyone have a connection
to Mr. McKinnon or the expert(s) he worked with? I would be interested in
learning more about their reasoning for this approach.

All the best,

Carl

On Mon, May 20, 2019, 4:06 PM robert bristow-johnson <
rbj at audioimagination.com> wrote:

>
>
> So this would be about Tideman Ranked-Pairs, or Schulze, or some other
> Condorcet-compliant method.
>
> It doesn't make much difference if the measure of Defeat Strength is
> Margins (supporting votes minus opposing votes), but what if Winning Votes
> is the measure of Defeat Strength in either RP or Schulze?  How should a
> pair of candidates that are equally-ranked on a ballot be counted?  Do you
> count it (as a winning vote) for *both* candidates?  For neither
> candidate?  (I dislike the idea of a half-vote for both candidates.  And I
> hate the idea of not allowing equal-ranking in a Condorcet RCV election.)
>
> What is the right way to do this?  It seems the most consistent might be
> to count an equally-ranked votes for **neither** candidate, since we
> consider unranked candidates as tied for last place on the ballot, and we
> would count those as votes.
>
> But what do you guys think?  If we allow for equal-ranking in a
> Condorcet-compliant RCV, how do we deal with it in terms of vote totals?
>
>
> --
>
> r b-j                         rbj at audioimagination.com
>
> "Imagination is more important than knowledge."
>
>
>
>
>
>
>
> ----
> Election-Methods mailing list - see https://electorama.com/em for list
> info
>

On Mon, May 20, 2019, 4:06 PM robert bristow-johnson <
rbj at audioimagination.com> wrote:

>
>
> So this would be about Tideman Ranked-Pairs, or Schulze, or some other
> Condorcet-compliant method.
>
> It doesn't make much difference if the measure of Defeat Strength is
> Margins (supporting votes minus opposing votes), but what if Winning Votes
> is the measure of Defeat Strength in either RP or Schulze?  How should a
> pair of candidates that are equally-ranked on a ballot be counted?  Do you
> count it (as a winning vote) for *both* candidates?  For neither
> candidate?  (I dislike the idea of a half-vote for both candidates.  And I
> hate the idea of not allowing equal-ranking in a Condorcet RCV election.)
>
> What is the right way to do this?  It seems the most consistent might be
> to count an equally-ranked votes for **neither** candidate, since we
> consider unranked candidates as tied for last place on the ballot, and we
> would count those as votes.
>
> But what do you guys think?  If we allow for equal-ranking in a
> Condorcet-compliant RCV, how do we deal with it in terms of vote totals?
>
>
> --
>
> r b-j                         rbj at audioimagination.com
>
> "Imagination is more important than knowledge."
>
>
>
>
>
>
>
> ----
> Election-Methods mailing list - see https://electorama.com/em for list
> info
>
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