Hi, Assuming I'm correctly understanding a voting method Stéphane Rouillon used in a recent message (excerpted below), which he called "Repetitive Condorcet (Ranked Pairs(Winning Votes)) elimination," it is unnecessarily complicated because it chooses the same winner as Ranked Pairs(Winning Votes), which of course is simpler.
Ranked Pairs(Winning Votes), also known as MAM, satisfies H Peyton Young's criterion Local Independence of Irrelevant Alternatives (LIIA). One implication of LIIA is that elimination of the last-ranked candidate(s) does not change the ranking of the remaining candidates. By the way, a different criterion has been masquerading as LIIA in Wikipedia. Peyton Young defined the real LIIA in his 1994 book Equity In Theory And Practice (if not earlier). --Steve -------------------------------------- Stéphane Rouillon wrote: -snip- > Let's try a counter-example: > > 3 candidates A, B, C and 100 voters. > Ballots: > 35: A > B > C > 33: B > C > A > 32: C > A > B > > Repetitive Condorcet (Ranked Pairs(winning votes) ) elimination would > produce > > at round 1: > 68: B > C > 67: A > B > Thus ranking A > B > C > C is eliminated. > > at round 2: > 67: A > B is the ranking > B is eliminated > > at round 3: > A wins. -snip- ---- Election-Methods mailing list - see http://electorama.com/em for list info
