Dear Craig, you wrote (2 March 2003): > Consider this (irv-wrong-winners, yet another wrong Mayor in > office) See that there is a large support rise for A and that > causes A to lose. > > > ---------------------------- > > A 19999 80004 > > B 1 5 > > BA 19997 19997 > > CB 40002 40002 > > DBA 20001 20001 > > ---------------------------- > > Total: 100000 160009 > > AV Winner: A B > > That looks like a "classical participation axiom" problem (but > it is not since B got 4 votes).
In your example, the fact that the winner is changed from candidate A to candidate B is caused only by the addition of the 4 B voters. Your conclusion that "the large support rise for A causes A to lose" is false. Actually, when IRV is being used and candidate A is the unique winner, then a set of additional voters who strictly prefer candidate A to every other candidate can never make candidate A lose. Markus Schulze ---- For more information about this list (subscribe, unsubscribe, FAQ, etc), please see http://www.eskimo.com/~robla/em
