How should complementarities affect antitrust merger policy? I introduce a two-stage strategic model in which complementary input sellers offer supply schedules to producers and then engage in bilateral bargaining with producers. The main result is that there is a unique weakly dominant strategy...

We show that in many applied economic models, it is possible to reduce the dimensionality of the space of actions to what we call sufficient decisions. We find that for monopoly and oligopoly in multi-sided markets and multi-product markets, the market equilibrium can be transformed into an...