Chapter 11 – Monopolistic Competition and Oligopoly (+ Appendix)
117. If the four-firm concentration ratio in an oligopolistic industry is 100 percent and each
firm has an equal percentage of sales, the Herfindahl Index is:
118. Assume six firms comprising an industry have market shares of 30, 30, 10, 10, 10, and
10 percent. The Herfindahl Index for this industry is:
119. Suppose the Herfindahl Indexes for industries A, B, and C are 1,200, 5,000, and 7,500
respectively. These data imply that: