We study sets of preferences containing some partial order. It appears that all preferences containing a certain partial order form a convex set of preferences with respect to the betweenness relation induced by the Kemeny distance for preferences. Moreover, the other way round these convex sets...

We consider voting rules on a multidimensional policy space for a continuum of voters with elliptic preferences. Assuming continuity, gamma -strategy-proofnessmeaning that coalitions of size smaller or equal to a small number gamma cannot manipulateand unanimity, we show that such rules are...