单选题 The marginal benefit from consuming the fourth unit of a product is $34, and the marginal cost to the producer of the fourth unit is $25. Under these circumstances, which of the following statements is most accurate?
  • A. Producer surplus is maximized.
  • B. The efficient quantity is less than four.
  • C. Producing and selling the fourth unit will increase efficiency.
【正确答案】 C
【答案解析】[解析] 如图所示，由于边际成本曲线是向右上方倾斜的，而边际收益曲线是向右下方倾斜的，从而生产和销售第四单位产品将使边际成本上升，同时使边际收益下降。本题中第四单位产品的边际收益高于边际成本，在上述两方面的影响下，边际成本与边际收益之间的差额将会减少，即更趋近于具有经济效率的均衡点E。生产者通过生产和销售第四单位产品，将使总效用的增加量大于总成本的增加量。因此，生产和销售第四单位产品将提高效率，本题的正确选项为C。 [*]