alt Hacker NewsIn the article it says:
To account for possible changes in package sizes, we focused on the price per unit, whether it was an ounce of salsa or a square foot of aluminum foil.
In the article it says:
To account for possible changes in package sizes, we focused on the price per unit, whether it was an ounce of salsa or a square foot of aluminum foil.
It doesn't say that they accounted for possible changes in item quality. Tide detergent claims that their new 80-oz bottle of laundry detergent can wash 64 loads just like the previous 100-oz bottle because it's more concentrated, and I suppose NPR (if they'd retained a sample of the previous product) could have brought that to a chemistry lab to test and verify that claim, but I have no idea how you'd objectively prove that an ounce of salsa had truly remained the same product.