A Comparison between the Core and the Monopoly Solutions in a Mixed Exchange Economy

Using a mixed market model for analyzing imperfectly competitive economies, we maximize the oligopolists'vVelfare Function, given individual rationality and feasibility constraints. We prove that solutions belong to the core for a large class of economies.This class includes, in particular, every monopoly having a single type of small traders. Note that all such solutions yield the large trader, utility-wise, strictly more than at any monopoly solution, where the monopolist plays strategically, and the ocean of small traders act as being as price-takers.