This paper analyzes the impact vertical integration has on upstream collusion when the price of the input is linear. As a first step, the paper derives the collusive equilibrium that requires the lowest discount factor in the infinitely repeated game when one firm is vertically integrated. It...

The hypothesis that vertically integrated firms have an incentive to foreclose the input market because foreclosure raises its downstream rivals' costs is the subject of much controversy in the theoretical industrial organization literature. A powerful argument against this hypothesis is that,...

We explore whether buyer groups, in which firms legally purchase inputs jointly, facilitate collusion in the product market. In a repeated game, abandoning the buyer group altogether or excluding single firms from them constitute more severe credible threats, hence, in theory buyer groups...

In a Bertrand-oligopoly experiment, firms choose whether or not to engage in cartel-like communication and, if so, they may get fined by a cartel authority. We find that four-firm industries form cartels more often than duopolies because they gain less from a hysteresis effect after cartel...