Recent anti-trust decisions have proposed remedies for tying of different computer software and applications. The remedies have drawn criticism for being ineffectual. This paper develops a model tailored to deal with the specific issue of tying in computer applications. It provides a rationale...

This paper considers the effect of exclusive contracts on investment decisions in a market with two upstream and two downstream firms. Segal and Whinston's (2000) irrelevance result is generalised and it is shown that exclusive contracts have no effect on the equilibrium level of internal...

We augment the multi-market collusion model of Bernheim and Whinston (1990) by allowing for firm entry into, and exit from, individual markets. We show that this gives rise to a new mechanism by which a cartel can sustain a collusive agreement: Collusion at the extensive margin whereby firms...