*1.3 A firm purchased copper pipes a few years ago at $10 per pipe and stored them, using them only as the need arises. The firm could sell its remaining pipes in the market at the current price of $9. For each pipe, what is the opportunity cost and what is the sunk cost?

1.4 In 2015, the U.S. Supreme Court was hearing a case about a federal rule to promote reduced electricity use. In discussing this rule, Chief Justice John Roberts related the regulation to the pricing of hamburgers:7

“If FERC is basically standing outside McDonald’s and saying, ‘We’ll give you $5 not to go in,’ and the price of the hamburger is $3 . . . the price of a hamburger is actually—I think most economists would say—$8, because if they give up the $5, they’ve still got to pay the $3.” L-9687