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 |
mutual majority? |
YES |
NO |
YES |
NO |
NO |
YES |
NO |
YES |
YES |
YES |
YES |
NO |
YES |
clone-independent? |
NO |
NO |
NO |
NO |
NO |
NO |
NO |
YES |
NO |
YES |
YES |
NO |
YES |
monotonic? |
NO |
YES |
YES |
NO |
NO |
YES |
YES |
NO |
NO |
NO |
YES |
YES |
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 |
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