[EM] UncAAO

[Forest W Simmons]

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