Even if the Federal Reserve Board crafts debit interchange regulations that are careful to exempt credit unions, CUs will still lose some debit interchange income from unfavorable network changes.

That is one of the conclusions of Interchange Regulation: Implications for Credit Unions, a paper the Filene Research Institute released today.

"Institutions with less than $10B in assets may be shielded from the 'reasonable and proportional' interchange standards, but they will still be subject to 'multi-homing'-the requirement that each card be capable of processing a transaction on more than one network," wrote report author Adam J. Levitin, an associate professor of law at Georgetown University Law Center in Washington, D.C. "Competition among networks will allow merchants to route transactions to the network that saves them the most money, which will push down income for issuers," he added.