A Set-Theoretical Comparison of C2 Social Choice Correspondences.

Given the choice sets produced by a pair of Condorcet social choice correspondence, the following intersting questions arise. Does one of these sets always contain the other? If not, do they always interest or on the contrary can they have an empty intersection? Laffond, Laslier and Le Breton (1995) answer these questions for Condorcet social choice correspondences based exclusively on the simple majority relation, callaed C1 choice correspondences by Fishburn (1977). In the present paper, we conduct the same task for five Condorcet correspondences that require the size of the majorities to operate.