I wish I knew more about the current practice of SPE. Who uses it the most? What are the customary procedures for setting the elimination agenda? When the status quo is on the agenda is it generally first on the list or last? Are the elimination votes mostly done one-by-one (roll call, show of hands, acclimation, etc. before going on to the next alternative on the agenda as in the old days? How large or dispersed does the assembly have to be before requiring rankings of all the options for use in an instant simulation of the method?
For any body that routinely makes use of the instant version of SPE that deduces the pairwise eliminations from a pairwise win/loss/tie matrix derived from ranked preference ballots, I urge you to consider applying the following procedure (based on exactly the same inputs used by the instant version of SPE) instead of SPE:
Initialize the variable X with the name of the last agenda item, assuming the agenda order is the customary order of least promising to most favorable.
... while X is covered by some other agenda item Y, reassign to X the name of the most favorable such Y.
The final value of X is the name of the winner.
[Y covers X iff Y beats or ties every Z that X beats or ties and strictly surpasses X in at least one case ... possibly beating a Z that X only ties or tying a Z that beats X, i.e. Y's row weakly dominates X's row in the win-tie-loss matrix.]
The set of uncovered alternatives is called the Landau set. So this method is Landau compliant. Copeland is also Landau compliant, but is less decisive and fails to preserve clone independence.
The prevous messages in this threadfollow:
Election-Methods mailing list - see https://electorama.com/em for list info
|Free forum by Nabble||Edit this page|