This paper provides a new theory for two-sided payment card markets. Adopting payment cards requires consumers and merchants to pay a fixed cost, but yields a lower marginal cost of making payments. Analyzing adoption and usage externalities among heterogeneous consumers and merchants, our...

This paper studies unintended consequences of price cap regulation in the presence of demand externalities in the context of payment cards. The recent U.S. debit card regulation was intended to lower merchant card acceptance costs by capping the maximum interchange fee. However, small-ticket...