Forest Simmons <[EMAIL PROTECTED]> writes: >To make this really simple, suppose that there is only one chooser, and >that there are three choices, and that the chooser prefers A to B to C to >A, with varying levels of intensity. Suppose that the chooser finally >decides to choose A. But before announcing her decision she finds out >that option B has been withdrawn. Is she going to stick with A? > >In other words, not even a dictator method can satisfy the IIAC at the >fundamental level of actual preferences.
I have to say that I don't think it makes sense for an individual to prefer A to B, B to C, and C to A. It's just logically contradictory. Individual preferences should be assumed to be transitive. What Condorcet discovered is that a set of individuals with transitive preferences between a set of options can sum up to a society that has intransitive preferences with regard to those options. Arrow's theorem is based on this idea. He believed that the possibility of intransitive social preferences was fundamentally disturbing, and in that I quite agree with him. Not only does it lead to ambiguous election results, but it also seems to be the source of the inevitable vulnerability of voting methods to strategic manipulation, which is a grave problem for majority rule voting. James ---- Election-methods mailing list - see http://electorama.com/em for list info