Sustaining Cooperation with Joint Ventures

Antitrust agencies and courts have expressed concerns that jointventures and strategic alliances between firms that competein other markets might serve to reduce the vigor of their competition.This article explores a mechanism through which a joint venturebetween two (or more) firms in one market can serve to facilitatecollusion in another market—even one unconnected verticallyor horizontally by costs or demand. In the models studied here,play in one market has the effect of altering players' beliefsabout their rivals' play in the second market. A joint venturein one market may provide a credible punishment mechanism forfirms colluding in another market. The joint venture may alsoprovide a vehicle for the transmission, between players, ofinformation in a way that helps cooperative types find eachother and collude in other markets. (JEL L12, L41, K21)