Tropicana has taken its "half gallon" orange juice container down to 59 ounces from 64, a fact I didn't notice (even though I buy about a container a week of the stuff) until I read a post about it by Steven Horwitz at the Coordination Problem blog:
If you eat tuna fish, you may have noticed the ongoing shrinkage in the size of the standard can of tuna, which used to be 6oz and is now 5oz. I have noticed Chunky soups going from 19oz to 18.5 and some canned tomato products going from 15oz to 14.5. Jody noted that the Dial bath bars we use have a new curved shape that makes them slightly smaller than they used to be....
the shrunken products sell for more or less the same price as the older, larger sized ones did. In the case of the juice, the standard price at my local grocery store has been around 2.99 for some time. Tuna prices have stayed about the same as well. But 2.99 for a slightly smaller carton is functionally equivalent to a higher price for the old, larger one.
Update: FutureOfCapitalism reader-watchdog-community member-participant-content co-creator D.G. emails a link to a New York Times article from January 2001 highlighting the practice.