I'd argue that this suggests another hypothesis that the article only partially considered: high interest rates are a cross-subsidy to attract the 40% of credit card users who never carry a balance, and the 40% of credit card users who never carry a balance are a marketing expense to normalize credit card use and make the 60% who do think it's completely acceptable to spend without a thought. I get literally thousands of benefits from the credit card company, and I don't pay a cent. That money has to be coming from somewhere, and I'd bet that it's coming from the 60% of consumers who pay usurious interest rates.