[EM] Markus: Copeland isn't Condorcet

[MIKE OSSIPOFF]

Mike Ossipoff wrote (16 Jan 2003):
>But in all Condorcet versions, a candidate wins if
>he has no pairwise decisions for or against him.

Markus replied:


Of course, that's not true.

Example:

A = B
A = C
A = D
A = E
A = F
B > C
B > D
B > E
B < F
C > D
C < E
C > F
D > E
D > F
E > F

Candidate A has no pairwise decisions for or against him.
However, e.g. Copeland chooses candidate B decisively.

I reply:

Copeland isn't a Condorcet version. Copeland is a Condorcet Criterion
method, but it isn't an interpretation of one of Condorcet's proposals
for solving circular ties.

(Now, just in case you've found a passage of Condorcet's writing in
which Condorcet _did_ propose Copeland, it's still true that Copeland
isn't one of the Condorcet proposals that we refer to when we say
"Condorcet". "Condorcet" is used to refer to interpretations of 2
proposals by Condorcet. One of those drops weakest defeats; the other
keeps strongest defeats).

Mike Ossipoff






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