[EM] A safe elimination method

Forest Simmons fsimmons at pcc.edu
Tue Sep 10 20:28:25 PDT 2013

This method requires complete preference ballots: no equal ranking nor
truncation allowed.  However it could be adapted to other types of ballots
including range ballots in various ways.


Let N be the number of candidates.  On every ballot insert approval cutoffs
in the N-1 spaces between the ranks.

Find the approval winners for each of the cutoffs.

Eliminate every candidate that is not an approval winner for any of the N-1

Find the new ranks on each ballot for the remaining candidates.

Repeat the process, until only one candidate remains.

I call this method "safe elimination" because, unlike superficial IRV, it
sounds the depths of the ranks at every stage of the elimination.

I am confident that the  Yee diagrams  of this method will exhibit none of
the pathologies that the Yee diagrams of IRV reveal.  And unlike Borda, it
does satisfy the Majority Criterion.

However, I do not believe this complete rankings version to be clone free
or burial resistant, let alone monotonic.  So at this stage it is just an
interesting idea meant to stimulate the imagination more than anything else.
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