Optimal Card Payment Systems

Abstract

This paper presents a model of a card payment system to address the pricing and rules that govern such systems. It evaluates the social optimality of privately set interchange fees and the adoption of a rule by payment systems to prevent merchants surcharging for card transactions using two extremes of merchant pricing - monopolistic pricing and perfect competition. Both types of merchant pricing constrain the ability of card schemes to use interchange fees and the no-surcharge rule in anticompetitive ways, although for quite different reasons. The positive role of the no-surcharge rule in preventing excessive merchant surcharging is also highlighted.

Keywords: Payment Systems, Banks, Credit, Debit Cards, Interchange Fees

JEL Classification: G21, L31, L42