Evaluation of ranked-ballot voting methods

Note that, according to Gibbard and Satterthwaite, all of the systems I am considering here are sometimes vulnerable to voter manipulation.  Satisfying the criteria I find important tends to minimize chances for manipulation.


Summary of the methods' criterion compliances

Baldwin Borda Bucklin Carey Coombs Copeland Dodgson Hare Nanson Raynaud Schulze Simpson Tideman
Pareto-optimal? YES YES YES YES YES YES YES YES YES YES YES YES YES
majority? YES NO YES YES NO YES YES YES YES YES YES YES YES
Condorcet? YES NO NO NO NO YES YES NO YES YES YES YES YES
monotonic? NO YES YES NO NO YES YES NO NO NO YES YES YES
clone-independent? NO NO NO NO NO NO NO YES NO YES YES NO YES
mutual majority? YES NO YES NO NO YES NO YES YES YES YES NO YES
Smith? YES NO NO NO NO YES NO NO YES YES YES NO YES
reverse-symmetric? NO YES NO NO NO YES NO NO NO NO YES NO YES
reinforcing? NO YES NO NO NO NO NO NO NO NO NO NO NO
Schwartz? NO NO NO NO NO NO NO NO NO NO YES NO NO
nonmanipulable? NO NO NO NO NO NO NO NO NO NO NO NO NO

# Coombs fails reinforcement
# precinct 1
8:B>C>A>D
6:C>D>A>B
4:D>B>C>A
# precinct 2
8:B>A>D>C
2:B>C>D>A
6:C>A>D>B
2:C>B>D>A
2:D>B>C>A


Back to Ranked-ballot voting methods

Robert Hampton “Honky” LeGrand III ’98