> Shrinkflation is the diminution in product quality and/or volume to resist raising prices due to inflationary pressure. This has been happening in the USA since roughly 2001.

This has been happening in the USA way before 2001:

> In 1967, the Fair Packaging and Labeling Act (FPLA) was enacted to ensure that consumers had enough information to make an informed choice between competing products. The Act requires each package of household "consumer commodities" included in the FPLA's coverage to have a label that includes the net quantity of contents in terms of weight, measure, or numerical count (measurement must be in both metric and inch/pound units).[10]

* https://www.stlouisfed.org/publications/page-one-economics/2...

* https://en.wikipedia.org/wiki/Fair_Packaging_and_Labeling_Ac...

> In fact, it was the humorist Art Buchwald who was among the first to sound the alarm. In a column entitled “Packaged Inflation” published in 1969, he lampooned the growing tendency to conceal price increases. Tongue in cheek, he praised American industry for “devising new methods to make the product smaller while making the package larger.”

[…]

> In late summer of 1974, for example, Woolworth’s offered a packet of pencils at its back-to-school sale for 99 cents – same price as the previous year. But as a sharp-eyed reporter at The New York Times observed, the packages only contained 24 pencils, six fewer than the previous year. The same strategy affected packets of construction paper (24 sheets, not 30).

* https://mikesmoneytalks.ca/shrinkflation-is-an-economic-mons...

And in recorded history for centuries:

* https://archive.ph/https://slate.com/news-and-politics/2022/...