Who Paid for Your Free Flight?

It's Tuesday, April twenty first, and welcome to HigherIQ. If you have a premium credit card, you probably love it. The sign-up bonus, the points on every purchase, the airport lounge where you can sit in a leather chair and drink free coffee while everyone else crowds around the gate. It feels like a gift. The bank is paying you to use your own money. But somewhere in the back of your mind, you've probably wondered: where does the money actually come from? The points have to be worth something, and someone has to be paying for them. The answer is that the person paying for your free flight is, in many cases, the person standing behind you in the checkout line who's paying with a debit card or cash. The credit card rewards system is one of the largest quiet wealth transfers in the American economy, and almost nobody who benefits from it knows how it works. Every time you swipe a credit card, the merchant pays a fee. This fee is called an interchange fee, and it goes from the merchant's bank to your bank, the one that issued your card. For a standard credit card in the US, the interchange fee averages about two percent of the transaction. For a premium rewards card, the kind that earns you three times points on dining or five times points on travel, the fee can be as high as three percent or more. On a hundred dollar dinner, the restaurant might keep only ninety seven dollars. The other three dollars goes to your bank. Your bank uses part of that fee to fund your rewards. The points you earn, the cash back you receive, the lounge access you enjoy, all of it is financed by interchange revenue. The math is straightforward: merchants pay higher fees on rewards cards, banks pass some of that revenue back to you as points, and you feel like you're getting something for free. But the merchant isn't absorbing the cost. The merchant is passing it on. Because most merchants are contractually prohibited from charging different prices for cash versus card purchases, or have historically been discouraged from doing so by the card networks, they set a single price for all customers. That price is high enough to cover the interchange fees they pay on card transactions. Everyone who buys a gallon of milk at that store pays the interchange-inflated price, whether they're paying with a premium Amex card or a twenty dollar bill. This means cash and debit card users are paying higher prices to subsidize a rewards system they don't participate in. The Federal Reserve Bank of Boston published a study quantifying this transfer. Their estimates found that the average cash-using household pays roughly $149 per year in implicit costs to card-using households, while the average rewards card household receives about $1,133 per year in benefits. A more recent NBER working paper estimated that interchange fees transfer approximately $30 billion every year from cash and debit card users to credit card users in the United States. Because credit card spending and rewards are strongly correlated with household income, the transfer is regressive: it flows from lower-income households to higher-income ones. Researchers have called this a "reverse Robin Hood" effect. The transfer is largest at the extremes. When the Boston Fed divided households into seven income categories, the gap between the poorest and richest was $771 per household per year. Households earning less than $20,000 paid about $21 annually into the system. Households earning over $150,000 received about $750. The person who can least afford to subsidize someone else's airline miles is the person doing the most subsidizing. There's a reasonable counterargument, and it deserves honest treatment. Critics of the "reverse Robin Hood" framing point out that cross-subsidies exist throughout the economy. Shopping centers offer free parking that benefits car owners more than bus riders. Sales and discounts benefit patient shoppers more than those who buy at full price. The question is whether the interchange transfer is large enough and regressive enough to warrant concern on its own. Reasonable people disagree. But the scale, $30 billion a year flowing in one direction, is hard to dismiss as trivial. This system is almost uniquely American. In 2015, the European Union capped interchange fees at 0.3 percent for credit cards and 0.2 percent for debit cards. The result was immediate: merchants saved an estimated six billion euros per year, and the lavish rewards programs that American cardholders take for granted largely don't exist in Europe. A European credit card might offer modest cash back or a small loyalty program, but nothing approaching the sign-up bonuses, tiered multipliers, and lounge networks that American premium cards provide. The rewards aren't better in America because American banks are more generous. They're better because American interchange fees are six to seven times higher than European ones, and those fees fund the rewards. The US has partially regulated this space. The Durbin Amendment, passed in 2011, capped interchange fees on debit card transactions at about twenty one cents plus 0.05 percent of the transaction. But Congress explicitly left credit card interchange fees untouched. This created a two-tier system: debit card fees are regulated, credit card fees are not. The gap helps explain why banks aggressively market credit cards over debit cards and why rewards programs are almost exclusively a credit card phenomenon. The sign-up bonus, the feature that gets the most attention in personal finance circles, exists because of customer acquisition economics. When a bank offers you seventy five thousand points for spending four thousand dollars in three months, it's making a bet on your lifetime value as a cardholder. If you carry a balance and pay interest, the bank earns far more than the cost of the bonus. If you pay in full every month, the bank still earns interchange revenue on every purchase you make for years. The largest US banks reported $41.3 billion in interchange fee income from credit cards in a recent year, alongside $89.7 billion in interest income and $9.9 billion in fee income. The rewards are expensive but the revenue streams they generate are enormous. This creates a strange incentive loop. Banks compete with each other by offering increasingly lavish rewards, funded by increasingly high interchange fees, which raise prices for everyone, which makes the rewards more valuable relative to those higher prices, which makes the cards more attractive, which increases card adoption, which increases the volume of interchange fees. The system feeds itself. The more people use rewards cards, the more everyone's prices go up, and the more valuable it becomes to have a rewards card. If you're inside the system, you're getting paid. If you're outside the system, you're paying for everyone else. The Durbin Amendment's experience is instructive about whether regulating interchange actually helps consumers. When debit interchange fees were cut, merchants saved billions. Studies found that large merchants did pass some of those savings on to consumers through lower prices, but not all of them. Banks, meanwhile, responded by eliminating free checking accounts and raising other fees to make up the lost revenue. The net effect on consumers was ambiguous. Regulating interchange doesn't make the costs disappear. It moves them around. So if this comes up in conversation, here's how to think about it. Credit card rewards are funded by interchange fees that merchants pay on every transaction, averaging about two percent in the US versus 0.3 percent in Europe. Because merchants set a single price for all customers, cash and debit users pay inflated prices to subsidize a system they don't benefit from. Federal Reserve researchers estimate this transfers roughly $30 billion a year from cash and debit users to credit card users, and the transfer flows disproportionately from lower-income households to higher-income ones. The rewards aren't free. They're paid for by everyone who shops at a store that accepts credit cards, whether they have a rewards card or not. Your points are real. Your free flight is real. The question is who paid for the ticket. Stay informed, stay curious, and we'll see you tomorrow.