In repeated normal-form (simultaneous-move) games, simple penal codes (Abreu, 1986, 1988) permit an elegant characterization of the set of subgame-perfect outcomes. We show that the logic of simple penal codes fails in repeated extensive-form games. By means of examples, we identify two types of...

We investigate the impact of vertical mergers on upstream firms' ability to sustain tacit collusion in a repeated game. We identify several effects and show that the net effect of vertical integration is to facilitate collusion. Most importantly, vertical mergers facilitate collusion through the...

In this paper we investigate the impact of vertical mergers on upstream firms’ ability to sustain collusion. We show in a number of models that the net effect of vertical integration is to facilitate collusion. Several effects arise. When upstream offers are secret, vertical mergers facilitate...

In repeated normal-form games, simple penal codes (Abreu 1986, 1988) permit an elegant characterization of the set of subgame-perfect outcomes. We show that the logic of simple penal codes fails in repeated extensive-form games. We provide two examples illustrating that a subgame-perfect outcome...