UncAAO stands for Uncovered, Approval, Approval Opposition. Here's how it works:
For each candidate X, if X is uncovered, then let f(X)=X, else let f(X) be the candidate against which X has the least approval opposition, among those candidates that cover X. Start with the approval winner A and apply the function f repeatedly until the output equals the input. This "fixed point" of f is the method winner. ["Approval opposition" of X against Y is the number of ballots on which X but not Y is approved.] This method requires a tally of both pairwise approval and pairwise ordinal information, but both are efficiently summable in N by N matrices, where N is the number of candidates. This method (UncAAO) is monotone, clone free, and always picks from the uncovered set, which is a subset of Smith. Zero info strategy is sincere. Even perfect info incentives for burial and betrayal are practically nil. As near as I can tell, the only bad thing about the method is the "tyranny of the majority" problem shared by most, if not all, deterministic methods. Comments? Forest ---- election-methods mailing list - see http://electorama.com/em for list info
