Forest Simmons said: > In the case of full rankings of three candidates, this residual method > seems to always gives the same result as the Kemeny order, MinMax, > Ranked Pairs, SSD, etc. for the original problem.
That's what I expected. It's quite reasonable to assume that a _ranked_ method will give a tie in the case 33 A>B>C 33 B>C>A 33 C>A>B and that if we add just one more voter, his vote will break the tie, so that we pick A in the case 34 A>B>C 33 B>C>A 33 C>A>B Indeed, it makes sense that a Condorcet method would at least respect reversal symmetry, since adding two voters with opposite preferences does not change the margin of any pairwise victory (ignore issues of truncation, so that the word "margin" does not inspire a new round of arguments). I'd have to think a bit before concluding that cancelling out the rotationally symmetric parts of the electorate would give the same result as Condorcet in the presence of a CW. I seem to recall Saari giving an example to the contrary. Anyway, thanks, Forest, for pointing out that a devotion to symmetry need not force one to support Borda a priori. Alex ---- For more information about this list (subscribe, unsubscribe, FAQ, etc), please see http://www.eskimo.com/~robla/em
