Forest and "[EMAIL PROTECTED]": Yes, all voting methods certainly are manipulatable. In fact, that was mathematically proven by Gibbard and Satterthwaite (Satterthwaite, Mark A.; "Strategyproofness and Arrow's Conditions: Existence and Correspondence Theorems for Voting Procedures and Social Welfare Functions"; Journal of Economic Theory; Vol. 10, No. 2; April, 1975; 187-217; #654). However, it remains true that some methods are more manipulatable than others. I am only claiming that IRV is LESS manipulatable than the primary w/runoff procedure when there are 4 or more candidates. With 3 candidates, given that voters sincere preferences do not change from one balloting to the next, they are mathematically equivalent; that is, they yield the same results. Does anybody know if a proof of this assertion, or something to the contrary, has been published? How about an example showing a case where the IRV is more manipulatable than the Plurality Primary w/Runoff.
SB > Date: Thu, 31 Jan 2002 02:23:24 EST > From: [EMAIL PROTECTED] > To: [EMAIL PROTECTED] > Subject: Re: Consensus?: IRV vs. Primary w/Runoff > > Forest wrote- > > All seriously proposed election methods are subject to manipulation, > because all require strategy to one degree or another to maximize expected > outcome, and all optimal strategies require information about the > intentions of the other players. > > ----- > D- Again -- his happens when there are 3 or more choices. > > N1 AB > N2 BA > > Add C > > C may (depending on the method being used) -- > > beat A and B > beat A lose to B > beat B lose to A > lose to both A and B > > More combinations, of course, with 4 or more choices. __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com
