I suspect DMC will lead to 2-party domination. See http://math.temple.edu/~wds/crv/IncentToExagg.html
and consider this same example under DMC. If the top-1, top-2, none, or all-3 of the candidates are approved by all (I do not care which, so long as you are consistent about it) then B wins. The six C>A>B voters realize that honesty does not pay and instead change their vote to A>C>B betraying their favorite (3rd party) candidate C. This causes A to win, regardless of who approves what (sicne A is a condorcet winner). MORAL: exaggeration pays in DMC... and the further reasoning reachable by clinking on the hyperlinks suggests to me that 2-party domination will happen under DMC voting. Now it has been suggested to me by Adam Tarr that Conodrcet method that allow equality rankings and that also use winnig votes not margins, can avoid the 2-party domination trap. So I suggest to Jobst Heitzig that he propose a DMC variant that does those things... what precisely should it be? And then we can ask what happens to 2-party dominance under (new)DMC. (If new-DMC actually exists. I have not thought about it.) ---- Election-methods mailing list - see http://electorama.com/em for list info