单选题 Consider two markets; one has a Herfindahl-Hirschman Index (HHI) of 50, while the other has a four-firm concentration ratio equal to 2%. Which of the following statements most accurately describes these two markets?
  • A. Both of these markets are monopolies.
  • B. The market with the HHI equal to 50 is very competitive, while the other market has low competition.
  • C. Both markets are highly competitive.
【正确答案】 C
【答案解析】An HHI concentration measure of 50 is very low, indicating a high degree of competition. A four firm concentration ratio of 2% indicates a high level of competition. For both the four-firm ratio and the HHI, the higher (lower) the concentration measure, the lower (greater) the degree of competition.