Surplus sharing in Cournot oligopoly

We characterize equilibria of oligopolistic markets where identical firms with constant marginal cost compete à la Cournot. For given maximal willingness to pay and total demand, we first identify all combinations equilibrium consumer surplus industry profit that can arise from arbitrary demand functions. Then, as a further restriction, fix the average above (i.e., first‐best surplus) possible triples surplus, profit, deadweight loss.