2. If Crusoe is producing 10 pounds of fish and 21 pounds of berries, what is his opportunity cost of an extra pound of berries? And what is his opportunity cost of an extra pound of fish? Explain your answers.

Solutions to Practice Problems 1. If Crusoe’s production is efficient, he is producing at a point on his PPF. His opportunity cost of an extra pound of berries is the quantity of fish he must give up to get the berries. It is calculated as the decrease in the quantity of fish divided by the increase in the quantity of berries as he moves along his PPF.