[EM] Variable Inferred Approval Sorted Margins Elimination

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[EM] Variable Inferred Approval Sorted Margins Elimination


This is my favourite Condorcet method that uses high-intensity Score ballots (say 0-100):

*Voters fill out high-intensity Score ballots (say 0-100) with many more available distinct scores
(or rating slots) than there are candidates. Default score is zero.

1. Inferring ranking from scores, if there is a pairwise beats-all candidate that candidate wins.

2. Otherwise infer approval from score by interpreting each ballot as showing approval for the
candidates it scores above the average (mean) of the scores it gives.
Then use Approval Sorted Margins to order the candidates and eliminate the lowest-ordered

3. Among remaining candidates, ignoring eliminated candidates, repeat steps 1 and 2 until
there is a winner.*

To save time we can start by eliminating all the non-members of the Smith set and stop when
we have ordered the last 3 candidates and then elect the highest-ordered one.


In simple 3-candidate case this is the same as Approval Sorted Margins where the voters signal
their approval cut-offs  just by having a large gap in the scores they give.

That method fulfils Forest's recent 3-candidate, 3-groups of voters scenarios requirements, resists Burial
relatively well and meets mono-raise. The motivation behind this version is to minimise any disadvantage
held by naive (and/or uninformed) sincere voters.

Chris Benham

Forest Simmons [hidden email]
Thu May 30

In the example profiles below 100 = P+Q+R, and  50>P>Q>R>0. 

I am interested in simple methods that always ...

(1) elect candidate A given the following profile:
P: A
Q: B>>C
R: C,

(2) elect candidate C given
P: A
Q: B>C>>
R: C,

(3) elect candidate B given
P: A
Q: B>>C  (or B>C)
R: C>>B. (or C>B)

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