An appropriate (interim) notion of the core for an
economy with incomplete information depends on the amount of information that
coalitions can share. The coarse and fine core, as originally defined by Wilson
(1978), correspond to two polar cases, involving no information sharing and arbitrary
information sharing, respectively. We propose a new core notion, the credible
core, which incorporates incentive compatibility constraints, and is based
on the idea that a coalition can coordinate its potential objection to a status-quo
over an event that can be credibly inferred from the nature of the objection being
contemplated. We provide sufficient conditions ensuring non-emptiness of the credible
core.