alt Hacker NewsPatrick McKenzie rebuts this here: (podcast) https://open.spotify.com/episode/2E2KRPcDvh1LcRw5bIsBms or here (article): https://www.bitsaboutmoney.com/archive/anatomy-of-credit-car...
The intuition being: people who carry balances and pay interest don't actually spend very much; they are not wealthy.
Replies
I think that's out of date. He links to a study showing interchange revenue net of rewards showing up to 3% by high FICO scores. (Just at a gut check that seems crazy to me, since interchange revenue doesn't really go much above 3%!). But that's from 2013. I remember when Fidelity launched its 2% flat cashback AmEx back in 2003. People didn't really know if it would be sustainable. Now 2% is a dime a dozen.
The most recent I've seen otherwise is this Federal Reserve study[0] from 2022. It finds that the marginal return on swipes is actually slightly negative because of how juicy rewards have gotten, and 80% of their profitability comes from interest (with most of the rest fees):
> we find that, on average, the credit function makes up approximately 80 percent of the credit card profitability, whereas the contribution of the transaction function is slightly negative, as rewards and other expenses on credit card transactions outpace banks' interchange revenues.5 In addition, fees—in particular late fees—comprise approximately 15 percent of credit card profitability.
[0] https://www.federalreserve.gov/econres/notes/feds-notes/cred...
Credit card companies make 3/4 of their revenue from interest. From Capital One's 10k, Net Interest Income vs. Total Net Revenue:
2023: 79.5%
2024: 79.8%
2025: 80.2%
That "intuition" is agreeing with the parent.
Patrick McKenzie is a dishonest industry insider that cannot be trusted on this topic, and therefore probably any other. Sophistry to an extreme.
Discussion of Patrick's article:
What does that graph tell you? Because I think patio11 wanted to send one message and people accidentally misunderstand the graph.
That's the interchange income corresponding to wealthy people. Interchange is paid by the card-accepting business, not by the buyer. The buyer pays interest and other fees and that graph looks very different.
From that original study the full picture table says in % of ADB that the "poorest" (below 620 FICO) pay ~45% interest and fees but bring only 2% additionally in interchange income. The wealthy (at 800+) pay ~10% interest and fees but bring another almost 10% interchange income, on 4 times higher spending, and 3 times higher rewards (so the wealthy get ~12 times higher rewards in $ value than the "poor").
Just the percentages paid by each group more than offset the difference in spending. There are also way more "poor" accounts than wealthy accounts. Intuitively you can tell that the banks are effectively subsidizing the fees and interest for the wealthy with the income from the poor, for the sake of the interchange income which is mostly generated by the wealthy but doesn't come from their pocket.
Those poorest of people (<620 FICO) pay more interest and fees (percentage and absolute terms) than any other group. There's a range in the middle on the wealth scale where the customers are actually a net loss for the banks (the 660-760 FICO range).