Net exports usually ________ when the U.S. economy is in a recession and ________ when the U.S. economy is expanding

Scientists have said for years cod was so seriously overfished in European Union waters that there was a risk of extinction due to stock collapse. Why would overfishing occur in this common market?

A) Fishing occurs until marginal cost per boat equals marginal social benefit which is inefficient. B) Fishing occurs until marginal social cost per boat equals marginal social benefit which is inefficient. C) Fishing occurs until marginal cost per boat equals marginal benefit which is inefficient. D) Fishing occurs until marginal social cost per boat equals marginal cost which is inefficient.

In the long run, a profit-maximizing monopolist

a. earns zero economic profit. b. produces the same amount as a perfectly competitive industry. c. receives a higher price for his output than a perfectly competitive firm. d. produces at the output level that minimizes his long-run average total cost.