Friday, September 17, 2010

Happy Birthday Marquis de Condorcet (1743-1994)

A French mathematician and philosopher most famous for developing a voting system to avoid majority cycling problems in cases involving choices among more than two options. In a three-way contest, a majority could prefer A over B, a different majority could prefer B over C, and still a different majority could prefer C over A. Condorcet's method, which is still used in some places, is to have voters rank-order candidates on a single ballot. The candidate with the highest average ranking across all ballots prevails. If that candidate would have defeated all others in head-to-head voting, then he or she is a clear Condorcet winner. For the most part, however, the Condorcet method leads to the selection of compromise candidates - candidates who may be ranked second on a large number of ballots, but not ranked first on any. Thus, the Condorcet method does not guarantee that anyone's preferred candidate will win. The method is also susceptible to strategic down-ranking of a candidate a certain group of voters does not prefer but perceives as a formidable challenger to their preferred candidate.

No comments:

Post a Comment

I actively moderate comments for spam, advertisements, and abusive or offensive language.