An elementary core equivalence theorem in a countable economy. (Q1862740)

The referred paper naturally extends the finite exchange economy model to the case of countably many traders. The fact that the core of such economy is empty leads to the attempt to modify its definition. It is done by strenghtening the demands putted to the coalition which ``improves upon'' the core outcomes. Namely, it is to involve costs, too. For this modification, the proof of the core equivalence is presented, and the non-emptiness of such core is shown, as well.