Kristofer, In answer to your question below.
I could be wrong because I am not sure of the total number of candidates in the contest, but I believe that the answer is "No, nonmonotonicity can occur even when the Condorcet candidate wins." This happened in the recent Aspen, CO city council election where if 75 fewer persons had voted for one of the candidates, he would have won, but I believe that the actual winner was the Condorcet winner, unless I'm mistaken. Perhaps you can look into it by contacting Aspen. I believe that the list of all voters' votes is available, but not the images of the original ballots to check the accuracy of that list. Kathy Message: 4 Date: Sat, 20 Feb 2010 10:56:09 +0100 From: Kristofer Munsterhjelm <[email protected]> To: EM <[email protected]> Subject: [EM] Simple monotonicity question Message-ID: <[email protected]> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Does nonmonotonicity in three-candidate IRV only happen when the Condorcet winner is eliminated? More generally, does a candidate-elimination method have to be able to eliminate the Condorcet winner in a three-candidate scenario in order to be nonmonotonic with only three candidates? ---- Election-Methods mailing list - see http://electorama.com/em for list info
