Collusion with Internal Contracting

In this paper, an infinitely-repeated Bertrand game is considered. The model has a two-tier relationship; two firms make a self-enforced collusive agreement and each firm writes a law-enforced contract to its privately-informed agent. The main finding is that in optimal collusion, interaction between intra-firm (internal) contracting and inter-firm collusion may be exploited; inter-firm collusion may enhance the efficiency of internal contract, and conversely, internal contracting may facilitate collusion