> my theory is that the decline in quality is another hidden form of inflation

That is a well-known phenomenon, usually called "shrinkflation". (After the fact that the easiest way to lower quality while keeping the price consistent is to just give you less stuff for the same price.)

Although all economists are made aware of the phenomenon, they seem to be just as prone to the illusion as anyone else. Here you can see Tyler Cowen weighing in on a Twitter debate about the price of a meal at Chipotle: https://marginalrevolution.com/marginalrevolution/2026/08/us...

A burrito is sold for the same price (well, 4.6% higher) now that it was 15 years ago. Case closed! Stop complaining about Chipotle's pricing.

Is it the same burrito? Deep in the comments "Michael" reports, from current and archived Chipotle menu tools, that a steak burrito bowl in 2015 contained 875 calories and the same exact menu order in 2026 contained 830 calories... with 80 calories out of that 45 calorie difference representing additional steak in the 2015 bowl.