In a perfectly competitive market, the good or service cannot differ substantially among sellers

To sell one more unit of a good, a monopolist must

A) lower the price on the last unit only. B) lower the price on all units. C) raise the price only on the last unit sold. D) raise the prices on all goods.

One reason why purchasing power parity may not work perfectly has to do with barriers to trade such as tariffs and quotas on imports

a. True b. False