Copeland's method: Difference between revisions

Copeland's method also passes [[ISDA]]; since the Copeland winner is always in the Smith set, all candidates in the Smith set must have higher Copeland scores than all candidates not in the Smith set, and since by definition candidates in the Smith set have a pairwise victory against every candidate not in the Smith set, adding or removing any number of candidates not in the Smith set will only result in every candidate in the Smith set having that number of pairwise victories added or subtracted from their total; since the original Copeland winner must have had a higher Copeland score than all other Smith set candidates in order to win, they will still have a higher Copeland score and thus still win.

 

# E Stensholt, "[http://www.electoral-reform.org.uk/publications/votingmatters/P2.HTM Nonmonotonicity in AV]"; Electoral Reform Society ''Voting matters'' - Issue 15, June 2002 (online).

# A.H. Copeland, A 'reasonable' social welfare function, Seminar on Mathematics in Social Sciences, University of Michigan, 1951.

# V.R. Merlin, and D.G. Saari, "Copeland Method. II. Manipulation, Monotonicity, and Paradoxes"; Journal of Economic Theory; Vol. 72, No. 1; January, 1997; 148-172.

# D.G. Saari. and V.R. Merlin, 'The Copeland Method. I. Relationships and the Dictionary'; Economic Theory; Vol. 8, No. l; June, 1996; 51-76.

 

[[Category:Smith-efficient Condorcet methods]]