Positive and Negative preferences (was Re: [EM] MC -1, 0, 1 --- STV hybrid

[Venzke Kevin]

 --- Craig Carey <research at ijs.co.nz> a écrit : > 
> 
>  >1. A candidate who is ranked number 1 on more than
> half  the ballots wins.
>  >2. If no result, if there is one and only one
> candidate who marked as
>  >Approved by the majority, then that candidate
> wins. If the set of
>  >candidates Approved by the majority has more than
> one member, then all
>  >non-members are eliminated and their preferences
> are transferred. If  a
>  >candidate now has a majority  then that candidate
> wins. If  not, then
>  >the numbered rankings are abandoned, and the
> winner is the candidate
>  >with the highest  Approvals minus  Disapprovals
> tally.
>  >3. If  there were no candidates who were Approved
> by the majority, then
>  >eliminate all candidates marked as Disapproved by
> the majority and
>  >transfer their preferences  and proceed as before.
>  >If  a candidate has a majority they win. If no
> result, then abandon the
>  >numbered rankings  and elect the candidate with
> the highest  Approvals
>  >minus Disapprovals score.
> 
> That is not all that clear and an example could have
> got more to take
> a meaning from the text.

Assuming I'm correct that everyone will only vote +1
or -1 when possible, I believe his system would work
like this:

1. Does someone have a majority of first-place
rankings?  If so, he wins, else continue.
2. If no candidate has majority approval, go to step
4.
3. Eliminate the candidates who don't have majority
approval, reallocate the (ranked) votes, and see if
someone now has a majority as in IRV.  If so, he wins,
else continue.
4. The candidate with the highest approval wins.

The approval scores are always separate from the
IRV-style vote count.  The voter basically fills out a
ranked ballot and an approval ballot for the same set
of candidates.

It should work very much like Majority Choice Approval
with more ranks.  The only thing is that lower
preferences rarely matter.  They're only considered if
at least two candidates have majority approval!

I'm sorry I don't understand the math you use.

Yours

Kevin Venzke

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