We study a cost allocation problem under asymmetric information, and show that the ex ante incentive compatible core is non-empty. We also obtain a non-emptiness result for the incentive compatible coarse core, which is one concept of an interim core.

In this paper we show that in quasilinear economies the incentive compatible coarse core is non-empty if agents are informationally small in the sense of McLean and Postlewaite (2002) and the strict core in each state is non-empty.