Russ, You wrote (Sat.Feb.26): "A more useful criterion is the normal (as opposed to Mike-style) criterion taken from Blake Cretney's website:
Name: Secret Preferences Criterion: SPC Application: Ranked ballots Definition: If alternative X wins, and some of the ballots are modified in their rankings below X, X must still win.
Condorcet does not pass this criterion, which tells us that voters have incentive to truncate in some cases if not routinely."
Woodall splits this somewhat oddly-named criterion into two fairly self-explanatory others:
"Later-no-Harm: adding a later preference to a ballot should not harm any candidate already listed", and
"Later-no-Help: adding a later preference to a ballot should not help any candidate already listed".
Condorcet passes neither of these, but your conclusion only applies to Later-no-Harm.
In WV Condorcet (BP/RP/MM/River), the two LNHs are not in balance (adding a later preference is more likely
to help than harm an already listed candidate) so that in the
Interesting. Your telling me that adding a preference is more likely to help than harm a higher-ranked candidate? That's non-intuitive if it's true. I can certainly see how adding a preference might help a particular higher-ranked candidate in certain circumstances, but I don't see how it could help on average for all the higher-ranked candidates. If it does, than I'd call that a fault of the election method. Can you prove that or point me to a proof?
zero-information case there is a random-fill incentive.
As Kevin Venzke just more-or-less pointed out, the right zero-information strategy in WV is to equal-rank the candidates
above some ("the") approval cutoff point and to strictly rank (random-filling if necessary) all the candidates below it.
And what if equal rankings are not allowed?
--Russ ---- Election-methods mailing list - see http://electorama.com/em for list info
