>===== Original Message From [EMAIL PROTECTED] ===== >From: "Narins, Josh" <[EMAIL PROTECTED]> >To: election-methods-list <[EMAIL PROTECTED]> >Subject: RE: [EM] Sports and 'The Condorcet Mindset' > >Well, with IRV, you could only manipulate the outcome if you had >near-perfect information on the votes of other people, otherwise your as >likely to undo your own strategy as fulfill it. > >Borda, by comparison, can be "utterly" manipulated with no information, >since you can bury someone all the way down to the bottom rung with impact. [...]
Josh: Not true. By the usual definition of "manipulation," an insincere vote must be rewarded, not punished, to qualify as manipulation. The Borda Count will punish an insincere vote in some cases, and that is actually an incentive to vote sincerely. If too many people sincerely put Nader between Bush and Gore, and voted either Bush>Nader>Gore or Gore>Nader>Bush, Nader would have been elected. Therefore, you need some information to successfully manipulate the BC, and there is only a limited an envelope of manipulability. In some cases, depending on the sincere preferences, a given voter type (such as a Gore>Bush>Nader voter) cannot successfully manipulate the outcome to his own advantage at all. As a start, maybe we could quantify the number of voters who could successfully manipulate the outcome in a particular example. Here's a simple example to kick off the game: 1 ABC 1 ACB 1 CAB 1 CBA 1 BCA 1 BAC Is the BC is more manipulable than IRV or plurality vote, in this case? If so, precisely how much more (in numbers)? SB ---- For more information about this list (subscribe, unsubscribe, FAQ, etc), please see http://www.eskimo.com/~robla/em
