With implementation of the Durbin Amendment approaching its four-year anniversary on Oct. 1, studies are accumulating that substantiate what the credit union industry argued all along during the enactment of the Dodd-Frank legislation.

The Federal Reserve Bank of Richmond, specifically, has published at least two studies in its Economic Quarterly by Zhu Wang and other researchers (third quarter of 2012 and third quarter of 2014). Some key points of the earlier study include:

• Interchange income to financial institutions with more than $10 billion in total assets under control has been substantially reduced. And, at least so far, interchange income to financial institutions with less than $10 billion has been shielded.

• Merchants as a whole have greatly benefited from the reduced interchange fees under the regulation. However, merchants specializing in small-ticket sales have been adversely affected and small merchants have reported seeing no benefit.

• The regulation's impact on consumers is less clear. However, there is limited empirical evidence on the change in retail prices. At the same time, 50% of debit rewards programs have been eliminated and another 18% are planned for elimination. In addition, there has been an approximately 25% increase in noninterest checking account fees.

To summarize the bullet points above, merchants are benefitting, while consumers and financial institutions are not. The words sound like an echo from five years ago.