单选题

Which of the following statements concerning the HerfindahI-Hirschman Index (HHI) is most accurate?

A、 The HHI is a useful measure of potential barriers to entry.
B、 An HHI of 0.05 would be analogous to having the market shared equally by 20 firms.
C、 The HHI is usually unaffected by mergers among the top market incumbents.

【正确答案】 B

【答案解析】

If there are M firms in the industry with equal market shares, the HHI equals 1/M. With 20 firms having equal shares, the HHI = 1/20 = 0.05.