Grocery Economics A man and his economist friend are having lunch. The man mentions that he's noticed something strange when he buys groceries each week. "I always buy a tub of margarine, but I've noticed that, even though it's the same price every time, there's less margarine in the tub. I can't figure out what's going on. "The economist friend nods with a knowing smile and responds "what you have there is a case of the Law of diminishing Margarinal returns."
