Hello Chris,
I have one generic comment on evaluation of different voting methods.
Examples that include both sincere votes and altered votes nicely demonstrate the possibilities of strategic voting, but when the voting method gets a pile of ballots to be counted, no knowledge of which votes are sincere is available. I'll modify one of the examples to show what I mean.
On Mar 24, 2005, at 18:11, Chris Benham wrote:
The first is copied from a Sep.22,04 James G-A post.
3 candidates: Kerry, Dean, and Bush. 100 voters. Sincere preferences 19: K>D>>B 5: K>>D>B 4: K>>B>D 18: D>K>>B 5: D>>K>B 1: D>>B>K 25: B>>K>D 23: B>>D>K Kerry is a Condorcet winner.
Altered preferences 19: K>D>>B 5: K>>D>B 4: K>>B>D 18: D>K>>B 5: D>>K>B 1: D>>B>K 21: B>>K>D 23: B>>D>K 4: B>D>>K (these are sincerely B>>K>D) There is a cycle now, K>B>D>K
The voting method sees only the altered votes. Although the sincere CW would be K, a voting method that elects K is not necessarily good. In this case votes "4: B>D>>K" were altered. But as well it could have been that those votes were sincere and for example votes "4: K>>B>D" were altered. Lets say that the sincere votes of those K supporters are "4: K>>D>B". If that was the case, then the sincere CW would have been D.
Since the voting method can not know which votes are sincere and which not, I guess it should behave as the votes given in the election were the sincere votes. I can't find any good examples where the voting method would be able to identify some votes as insincere. Maybe in the case that all ballots that have X in the first place are identical one could guess that X supporters have agreed some strategy. But of course that could as well be their sincere uniform opinion.
So, it looks to me that in the example above the voting methods should behave as if there was a sincere cycle and not favour K any more than the others.
The best voting methods or voting organizers can do in this situation is to try to discourage strategic voting.
Best Regards, Juho
((P.S. One possible deviation to this main rule is a voting method that is known to require some certain strategy from the voters (to give the best results). In this case one could assume in the result counting process of the voting method that all voters have voted according to this known strategy and results should therefore be calculated using this assumption. In this case the voting method of course could give unwanted results if all or majority of voters voted sincerely. Maybe one should redefine sincerity in this case => sincere votes are those that follow the recommended/expected voting practice and do that in the light of voter's sincere preferences.))
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