My grocery store prints the unit price (price per ounce for example) as well as the product price on the shelf under the product display. This makes a decrease in the product weight for the same price obvious since the unit price increases. Don't most grocery stores do this?

Edgar replies: Many stores have unit pricing, but to detect a change in the price per ounce, the shopper would have had to memorize what it was previously. I don't know any shopper who does that.