Cooperation among competitors: some economics of payment card associations

We analyze platforms in two-sided markets with network externalities, using the specific context of a payment card association. We study the cooperative determination of the interchange fee by member banks. The interchange fee is the "access charge" paid by the merchants' banks (the acquirers) to cardholders' banks (the issuers). We develop a framework in which banks and merchants may have market power and consumers and merchants decide rationally on whether to buy or accept a payment card. After drawing the welfare implications of a cooperative determination of the interchange fee, we describe in detail the factors affecting merchant resistance, compare cooperative and for-profit business models, and make a first cut in the analysis of system competition.