Dear Steph, the participation criterion says that it is not possible to worsen the outcome by participating:
Suppose that candidate A is the winner. Suppose that a set of voters, where each voter strictly prefers candidate B to candidate A, is added to the original profile. Then candidate B must not become the new winner. Moulin demonstrated that the Condorcet criterion and the participation criterion are incompatible. (Herve Moulin, "Condorcet's Principle Implies the No Show Paradox," Journal of Economic Theory, vol. 45, pp. 53-64, 1988.) Markus Schulze ---- For more information about this list (subscribe, unsubscribe, FAQ, etc), please see http://www.eskimo.com/~robla/em
