The Economics of Interchange Fees and Their Regulation: An Overview

This essay surveys the economic literature on interchange fees and the debate over whether interchange should be regulated and, if so, how. We consider, first, the operation of unitary payment systems, like American Express, in the context of the recent economic literature on two-sided markets, in which businesses cater to two interdependent groups of customers. The main focus is on the determination of price structure. We then discuss the basic economics of multi-party payment systems and the role of interchange in the operation of such systems under some standard, though unrealistic, simplifying assumptions. The key point of this discussion is that the interchange fee is not an ordinary price; its most direct effect is on price structure, not price level. We then examine the implications for privately determined interchange fees of some of the relevant market imperfections that have been discussed in the economic literature. While some studies suggest that privately determined interchange fees are inefficiently high, others point to fees being inefficiently low. Moreover, there is a consensus among economists that, as a matter of theory, it is not possible to arrive, except by happenstance, at the socially optimal interchange fee through any regulatory system that considers only costs. This distinguishes the market imperfections at issue here for multi-party systems from the more familiar area of public utility regulation, where setting price equal to marginal cost is theoretically ideal. Next, we consider the issues facing policy makers. Since there is so much uncertainty about the relation between privately and socially optimal interchange fees, the outcome of a policy debate can depend critically on who bears the burden of proof under whatever set of institutions and laws the deliberation takes place. There is no apparent basis in today's economics - at a theoretical or empirical level - for concluding that it is generally possible to improve social welfare by a noticeable reduction in privately set interchange fees. Thus, if antitrust or other regulators had to show that such intervention would improve welfare, they could not do so. This, again, is quite unlike public utility regulation or many areas of antitrust including, in particular, ordinary cartels. By the same token, there is no basis in economics for concluding that the privately set interchange fee is just right. Thus, if card associations had to bear the burden of proof - for example, to obtain a comfort or clearance letter from authorities for engaging in presumptively illegal coordinated behavior - it would be difficult for them to demonstrate that they set socially optimal fees. We take a pragmatic approach by suggesting two fact-based inquiries that we believe policymakers should undertake before intervening to affect interchange. First, policymakers should establish that there is a significant market failure that needs to be addressed. Second, policymakers should establish that it is possible to correct a serious market imperfection, assuming one exists, by whatever intervention they are considering (such as cost-based regulation of interchange fee levels) and thereby to increase social welfare significantly after taking into account other distortions that the intervention may create. We illustrate both of these points by examining the recent Australian experience.