Standard economics provides a well-understood framework of the competitive determinants of market prices that is now widely accepted for antitrust analysis. In “two-sidedmarkets,” where firms supply products demanded by two interrelated groups of consumers, these competitive forces operate...

I extend Shy and Wang's (2011) model and study the problem of successive monopoly when complementarity is imperfect. In my model, consumers value the good no matter they pay in cash or by card. However, they are willing to pay a higher price if they can enjoy additional card service. Since...