the straightforward counterstrategy for those who prefer B to C is easy and requires no insincere rankings (as would wv require): They just need to vote their sincere rankings and approve of B and everything above B.
How is this more insincere than the option in winning votes? Why is insincere equal-ranking more insincere than insincere approval? This seems like a value judgement that can't really be supported. The two forms of insincerity are not really comparable.
I said so various times, but you continue talking about the 17% alone without considering the whole situation. Obviously, when we are talking about counterstrategy, the relevant group of voters is those who prefer the sincere winner to the manipulated winner, in this case all who prefer B to C. This group has in DMC a sincere counterstrategy, but needs insincere equal-ranking in winning votes.
The reason you look at a subgroup is because you want to figure out the optimal strategy for an individual voter. A voter can only decide his or her own vote, not the vote of all who share a particular pairwise preference or even all like-minded voters. The analysis I did shows that _each individual voter_ in that faction has the incentive for favorite betrayal.
I consider it considerably less relevant what kind of counterstrategies some small and special subgroup of those who prefer the sincere winner has.
In my opinion, considering the incentives of individual voters is the most fundamental building block of strategic voting analysis. Why may we ignore the favorite betrayal need of a large number of voters? Just because some other voters who share one pairwise preference with them have not voted in he way that our faction would like? Can you imagine explaining that to the voter?
"Yes, you need to bury Nader below your approval cutoff so that Gore can win. But it's not a big deal. It's just because some other Nader supporters won't approve Gore, and because some Gore voters approved Bush. It's their fault for being non-strategic. It's not the method's fault. You're just cleaning up the mess they made."
All favorite betrayal incentives are significant, even if there is another strategy for a majority that could avoid it! The only thing worth debating in my opinion are how often the situation would arise, leading to the question of how much of a problem it really is.
Regards,
Adam
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