Steph wrote: >This amazes me. >You are not the first to tell me Borda and Condorcet are "equivalent". >It could be the case in term of determining the winner when there is a >Condorcet winner.
Nanson is a Borda-elimination method (read: NOT the classic Borda count) and is Condorcet compliant. The classic Borda count is NOT Condorcet compliant. >However, Borda is not cloneproof and I always believed Condorcet methods were. Well, the good Condorcet methods (like Ranked Pairs and SSD/Beatpath) are. But not all Condorcet-compliant methods are. Consider this super-simple Condorcet method: 1) Compute a pairwise matrix from ranked ballots. 2) AT RANDOM, draw two candidates out and compare them pairwise. Eliminate the losing candidate. 3) Repeat step 2 until only one candidate remains. Declare this candidate the winner It is trivial to see that this is not clone independent. For example, say A>B>C>A is a three way tie. Normally, this method gives each candidate a 1/3 chance of winning. Now, add 10 clones of A and 10 clones of B to the election. One of the A clones now wins the election roughly 99.9% of the time. So, clone-independence is not a feature of all Condorcet methods - only the best ones. ---- Election-methods mailing list - see http://electorama.com/em for list info
