Adam- I like your geometric proof. However, I'm rusty on geometry. For a given triangle, will the perpendicular bisectors of its 3 sides always meet at a single point?
Also, when working in issue space, I assume you're measuring the distance between two points (x1, y1) and (x2, y2) as |x1-x2| + |y1-y2|. I don't think it matters for this case, but it seems more logical than using the pythagorean theorem. On the subject of Donald's proposal of IRV-completed Condorcet, right after sending the message I realized it would be non-monotonic. However, it looks like IRV may catch on in the US in the next few years. We have yet to reach consensus amongst ourselves on resolving cyclic ambiguities, so if IRV catches on it might make sense to propose it as the "backup." Keeping a pre-existing method as backup satisfies the cautious, and using a method that the public has already accepted avoids debates over the many different proposals for resolving cycles. I know people on this list tend to dislike IRV (I'm no fan), but I always maintain that progress is about improvement rather than perfection. The Condorcet first step does cure one flaw of IRV: The Hitler-Stalin-Washington case. The whole idea of HSW is that there's a unifying figure who commands respect (albeit not first-place support) from other camps, and IRV fails to elect him. However, in the presence of a cycle it's impossible for any figure to say "I'm a uniter, not a divider" since the electorate can always point to another candidate and say "Oh, yeah? We'll take this other guy over you." Hence the HSW case doesn't really apply. So, overall, I'd say IRV-completed Condorcet is better than IRV, even if other methods might be preferable. Alex ---- For more information about this list (subscribe, unsubscribe, FAQ, etc), please see http://www.eskimo.com/~robla/em