Collusion between non-differentiated two-sided platforms

Platform competition can be intense when offering non-differentiated services. However, competition is somewhat relaxed if platforms cannot set negative prices. If platforms collude they may be able to implement the outcome that maximizes industry profits. In an infinitely repeated game with perfect monitoring, this is feasible if the discount factor is sufficiently large. When this is not possible, under some condition, a collusive outcome with one-sided rent extraction along the equilibrium path can be sustained that leads to higher profits than the non-cooperative outcome.