IN 1966 a medical journal identified a condition it dubbed “credit-carditis”: lower-back ache, with pain radiating down the leg—caused by a back-pocket wallet stuffed with plastic. Payment cards still inflict pain of a different sort. American merchants paid more than $40 billion to process debit- and credit-card transactions in 2015. Despite a reform by the Federal Reserve in 2011 aimed at reducing these costs, revenue from these so-called “interchange fees” has more than doubled since the financial crisis. Retailers are still in revolt; banks are still resisting. That is not surprising, since they rely on the fees for a large and growing share of their income.

American consumers favour debit and credit cards over cash by more than two to one. But this convenience comes at a cost. The seller is charged a fee for every card purchase: in America, typically 0.5% to 3% of its value. These fees are set by payment-card networks, such as Visa and MasterCard and collected by card issuers, such as Wells Fargo and JPMorgan Chase. Some portion of these fees is borne by consumers, including those who pay by cash, in the form of higher...Continue reading