> here is an interesting paper by Ron Rivest: > > http://people.csail.mit.edu/rivest/RivestShen-AnOptimalSingleWinnerPreferentialVotingSystemBasedOnGameTheory.pdf
Very interesting paper. It contains a very good rationale for using a random election method (when there is a Condorcet cycle). The GT method in the paper is intriguing. It meets the Condorcet criterion, but if there is a Condorcet cycle then it does not necessarily meet the Pareto criterion! As the paper says, one of the defeats in the Condorcet cycle could be unanimous but the GT method would probably assign all candidates in the cycle a positive probability of winning. (Though the paper claims this can be done with a 3-cycle, it seems to me that you would need at least a 4-cycle.) Is anyone willing to reconsider the Pareto criterion in the case of a Condorcet cycle? I don't know if I am, but it's worth thinking about. Andy Jennings ---- Election-Methods mailing list - see http://electorama.com/em for list info
