Partly motivated by the recent antitrust investigations concerning Google, we develop a leverage theory of tying in two-sided markets. We analyze incentives for a monopolist to tie its monopolized product with another product in a two-sided market. Tying provides a mechanism to circumvent the...

This paper analyzes international antitrust enforcement when multinational firms operate in several markets with antitrust authorities in each market. We are concerned with how the sustainability of collusion in one local market is affected by the existence of collusion in other markets when...

This paper analyzes dynamic cartel formation and antitrust enforcement when firms operate in demand-related markets. We show that cartel prosecution can have a knock-on effect: desisting a cartel in one market reduces profits and cartel stability and leads to the break-up of the cartel in the...