Black's method

Black's method is an election method proposed by Duncan Black in 1958 as a compromise between the Condorcet method and the Borda count. This method selects a Condorcet winner. If a Condorcet winner does not exist, then the candidate with the highest Borda score is selected.^[1]

Properties

Among methods satisfying the majority criterion, Black's method gives the minimum power to the majority and hence the method is best at protecting minorities.^[2]

Satisfied criteria

Black's method satisfies the following criteria:

• Unrestricted domain
• Non-imposition (a.k.a. citizen sovereignty)
• Non-dictatorship
• Homogeneity
• Condorcet criterion
• Majority criterion
• Pareto criterion (a.k.a. unanimity)^[3]
• Monotonicity criterion^[3]
• Majority loser criterion^[3]
• Condorcet loser criterion^[3]
• Reversal symmetry^[3]
• Resolvability criterion
• Polynomial time

Failed criteria

Black's method does not satisfy the following criteria:

• Mutual majority criterion^[2]
• Smith criterion^[3]
• Participation^[3]
• Consistency^[3]
• Independence of Smith-dominated alternatives
• Independence of clones
• Independence of irrelevant alternatives
• Local independence of irrelevant alternatives
• Sincere favorite criterion