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...

Market organization significantly affects total output and incentives for firms to invest. I compare three types of market organization. In a market with search and random matching, total output is excessive and there are incentives for inefficient underinvestment. In a market with a monopoly...