[EM] Improved Copeland (was "A New Spinoff of Our Recent Discussions")

Kristofer Munsterhjelm km_elmet at t-online.de
Sat Jun 8 02:54:38 PDT 2019

On 08/06/2019 00.04, Forest Simmons wrote:
> I knew it was too good to be true!
> Kristofer,
> I forgot that when we worked on decloning Borda that we tried this
> fixing Copeland.  That wa a long time ago.  We must be getting old!
> I think you have found the cure for failure of mono-raise (if not for
> mononucleosis itself)..

Another possibility would be to let the pairwise contest (A vs B) be B's
penalty after eliminating A from every ballot. Then A-top ballots no
longer obscure B's penalties.

However, I'm not sure if that could produce cycles that would still lead
to a monotonicity failure, or if the monotonicity failure would depend
on the method in question.

Such an approach reminds me of UncAAO:

> To make it clone proof let's try using explicit approval cutoffs and
> calculate the penalities by fractional approval.
> We can appeal to the convention that a true clone is not split by an
> approval cutoff.  Otherwise, Approval itself based on ranked ballots
> with approval cutoffs would be clone dependent.
> Another advantage of using fractional approval for the penalty counts is
> that the method then distinguishes between
> 49 C
> 26 A>>B
> 25 B
> and the same profile with A>>B replaced by A>B>>..
> yielding the respective winners C and B in the two cases.
> Does that fix everything?
I think that would work (I'd have to check in detail when I have more
time), but I very much prefer methods that don't need Approval cutoffs.

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