The Hidden History of Credit Cards: How Consumer Debt Became Infrastructure

On a February evening in 1950, a New York businessman named Frank McNamara finished dinner at Major’s Cabin Grill in Manhattan and reached for his wallet — which he had left at home. His wife had to rescue him, paying the check while McNamara sat in the particular humiliation of a man who cannot cover his own dinner tab. The anecdote is probably embellished in its details, but McNamara took the experience seriously enough that within months he had founded the Diners Club, issuing cardboard charge cards to roughly 200 New York restaurant customers. By the end of 1950, Diners Club had 20,000 members. By 1951, it was turning a profit.

What McNamara had solved was not primarily a consumer finance problem. It was a coordination problem. Restaurants wanted customers who could spend freely without worrying about carrying cash. Customers wanted the convenience of a running tab. But no single restaurant could extend credit to strangers — the information and enforcement costs were prohibitive. What a card network could do was aggregate the credit function across many merchants and many customers, spreading the information costs and making the whole system economically viable for everyone involved. The consumer convenience was real, but it was a byproduct of solving the merchant problem first.

This origin story matters because it sets the template for everything that followed. The credit card was conceived as infrastructure — a payment system that intermediated between merchants and consumers — and its financial characteristics were optimized not for consumer welfare but for the sustainability and profitability of that intermediation. Every subsequent development in the industry, including the ones most harmful to consumers, follows directly from that original design logic.

The Invention of Revolving Credit

The Diners Club model was a charge card, not a credit card in the modern sense. You paid your balance in full each month. The innovation that transformed the industry — and created the debt machine that now constitutes one of the most profitable product lines in banking history — was the introduction of revolving credit.

Bank of America launched the BankAmericard in Fresno, California in 1958. It was the first true mass-market bank credit card with revolving credit: you could carry a balance from month to month, paying interest on the unpaid amount. The Fresno rollout involved a mass mailing of 60,000 unsolicited cards to Fresno residents — an approach that would later be banned as too reckless even by the lenient standards of mid-century American banking regulation. The early results were catastrophic: fraud rates were enormous, many recipients had no idea what the card was or how it worked, and losses in the first year nearly killed the program.

BankAmericard survived, grew, licensed its model to other banks across the country, and eventually became Visa in 1976. MasterCharge — which became Mastercard — emerged from a competing bank consortium on a nearly identical trajectory. By the 1970s, the revolving credit card was a fixture of American consumer finance, and by the 1980s it had begun spreading to the rest of the world.

The financial model that made revolving credit so profitable deserves examination in some detail, because it is built on a mechanism that is unusual even by the standards of consumer financial products. A revolving credit card earns money in two distinct ways. The first is the interchange fee — roughly 1.5 to 3 percent of every transaction — paid by the merchant to the card network and split between the issuing bank and the network itself. This fee is charged on every transaction, whether or not the cardholder carries a balance. The second is interest — in the United States, averaging around 20 percent annually, and historically ranging as high as 30 percent — charged only on carried balances.

These two revenue streams serve different customer segments. Interchange fees are paid primarily by merchants on behalf of high-income customers who pay their bills in full each month, use premium rewards cards, and never pay a dollar in interest. Interest charges are paid primarily by lower-income customers who carry balances — often because they lack the cash reserves to pay their bills at the end of the month. The economics of the credit card system thus involve a systematic transfer from lower-income consumers (through interest) and from all consumers via higher retail prices (through interchange) to card network shareholders and to the reward programs that benefit high-income users.

How Deregulation Created the Modern Debt Machine

The credit card industry in 1978 was a substantially different beast from what it would become within twenty years. State usury laws in most of the United States capped interest rates on consumer loans, limiting what banks could charge revolving cardholders. These caps constrained profitability and, more importantly from the industry’s perspective, made it difficult to extend credit to higher-risk borrowers who would be charged premium rates under a deregulated system.

In 1978, the Supreme Court decided Marquette National Bank of Minneapolis v. First of Omaha Service Corp., holding that a bank could export the interest rate laws of its home state to customers in any state where it operated. The practical implication was immediate: banks could escape state usury caps by incorporating their credit card operations in states with no meaningful rate limits. South Dakota, facing economic stagnation, eliminated its usury ceiling in 1980 to attract Citibank’s card operations. Delaware followed. Within a decade, virtually every major credit card issuer had relocated its operations to one of these two states, and the national effective cap on credit card interest rates had been eliminated entirely.

The consequences were exactly what you would predict. Credit card profitability exploded. Credit card interest rates, which had averaged roughly 18 percent in 1980, barely moved as the federal funds rate fell from double digits to single digits — the pass-through of lower borrowing costs to consumers essentially stopped working. The spread between the banks’ cost of funds and their credit card lending rates widened from roughly 4-5 percentage points in the early 1980s to 10-15 percentage points by the 1990s and beyond. The deregulation had created, in the industry’s own phrase, a “stickiness” in credit card rates that had no equivalent in mortgage or auto lending — because unlike mortgage or auto loans, credit cards faced no competitive discipline from the secondary market.

The industry also innovated its fee structure with considerable creativity during this period. Late fees, which barely existed in 1980, became a major profit center. Over-limit fees emerged as a product feature rather than a deterrent. Universal default provisions allowed issuers to raise rates on cardholders who were late on other creditors’ bills. Minimum payment requirements were set low enough — sometimes as low as 2 percent of the balance — that a cardholder making minimum payments on a $5,000 balance could spend fifteen or twenty years paying it off, generating interest charges that exceeded the original principal several times over.

Credit Cards as Economic Infrastructure

Despite its predatory features, the credit card system became genuinely indispensable in ways that created real switching costs for both consumers and the economy as a whole. This transformation — from a convenience product to critical infrastructure — happened gradually through the 1980s and 1990s as the payment network effects of Visa and Mastercard became self-reinforcing.

By the time a card network reaches sufficient merchant acceptance, consumers cannot easily switch to non-card payment methods without real inconvenience, because the merchants they patronize have organized their operations around card acceptance. By the time sufficient consumer card carrying exists, merchants cannot easily refuse card acceptance without losing customers. The result is a two-sided network that becomes progressively more entrenched as it grows, creating barriers to entry that have kept Visa and Mastercard in a duopolistic position for decades despite numerous attempts at competition.

The internet accelerated this lock-in dramatically. Online commerce, which grew from a curiosity to a major fraction of retail spending between 1995 and 2010, required a payment method that worked across distance and without physical cash. Credit and debit cards were the only such payment method with sufficient merchant acceptance and consumer trust to serve this function. The result was that the card networks became the plumbing of e-commerce: invisible, essential, and enormously profitable precisely because their centrality made alternatives impractical.

This infrastructure status has important policy implications that are rarely discussed clearly. When a private payment system becomes so deeply embedded in commerce that it is de facto critical infrastructure, the policy case for treating it as such — subjecting it to common-carrier obligations, rate regulation, or public ownership — becomes correspondingly stronger. The European Union has moved significantly further in this direction than the United States, capping interchange fees and imposing interoperability requirements that have partially redistributed the system’s rents away from card networks and toward merchants and consumers. The results have been largely positive: lower retail prices, reduced barriers to new payment method entry, and no discernible reduction in credit availability.

The Moral Architecture of Consumer Debt

The most honest account of how the credit card system works requires confronting a feature that the industry has always preferred to obscure: the model is most profitable when its customers are in financial distress. This is not a design flaw — it is the design.

A customer who pays their balance in full every month generates interchange revenue for the issuer but no interest income. A customer who carries a high balance, makes minimum payments, and occasionally pays fees is the most valuable customer the issuer has. The industry’s risk models, credit line extension decisions, and marketing strategies are all calibrated around identifying and cultivating the latter group — people with sufficient income to service debt but insufficient financial cushion to pay it off.

The subprime credit card expansion of the 1990s and 2000s was the logical endpoint of this model. Banks extended cards to customers with poor credit histories, knowing that default rates would be high but that interest rates of 25-30 percent more than compensated. When defaults eventually spiked — as they did during the 2008 financial crisis — the issuers had already extracted enough in interest payments from the surviving accounts to remain profitable in aggregate. The individual customers who defaulted had paid far more than they borrowed and still ended up in financial ruin.

The consumer protection reforms that followed — the CARD Act of 2009, in the United States — addressed some of the most egregious practices: arbitrary rate increases, retroactive rate hikes, fee pyramiding. They did not address the fundamental structure of a business model that profits most from the financially vulnerable. That structure remains intact, and the interest rates that made it profitable remain at historic spreads over the banks’ cost of funds.

The credit card is a genuine piece of economic infrastructure that facilitates billions of transactions and provides real value to consumers. It is also a mechanism that has transferred enormous wealth from lower-income consumers to financial institutions and to the high-income consumers whose rewards programs are subsidized by that transfer. Both things are true simultaneously, and any honest assessment of consumer finance has to hold both. McNamara’s embarrassment at Major’s Cabin Grill set off a chain of events that created something simultaneously indispensable and exploitative — which is, perhaps, the most accurate description of most of what passes for financial innovation.