For Wilma, peanut butter and jelly are perfect substitutes. She is willing to trade two ounces of jelly for one ounce of peanut butter. For Fred, the two commodities are perfect complements. He consumes 2 ounces of peanut butter with 1 ounce of jelly. Assume that the quantity of peanut butter is fixed at 20 ounces and the quantity of jelly is fixed at 20 ounces. Below is the Edgeworth Box for the situation described. As shown, Wilma is in the lower left corner and Fred is in the upper right cor- ner, peanut butter is on the vertical axis and jelly is on the horizontal axis. 11 Wilma 10 11 12 13 14 15 16 17 18 19 20