Games Played in a Contracting Environment

We analyze situations where a player must contract with the monopoly supplier of an essential input in order to play an action in a strategic form game. Supplier monopoly power does not distort the equilibrium distribution over player actions under private contracting, but may dramatically affect the equilibrium actions under public contracting. When a player randomizes between actions, suppliers for the different actions behave as though they are producing perfect substitutes when contracts are private; when contracts are public, it is as though they are producing perfect complements.