Chapter 6 Equity: Concepts and Techniques 29
6. Under the assumption that the total worldwide revenue of all firms in this industry was $250 billion,
the market shares of the top five corporations are the following:
AOL Time Warner: $38 billion/$250 billion = 15.2%
Walt Disney: 25/250 = 10.0%
a. The three-firm concentration ratio is the combined market share of the largest three firms in the
industry = 15.2 + 10 + 10 = 35.2%.
The five-firm concentration ratio is the combined market share of the largest five firms in the
industry = 15.2 + 10 + 10 + 9.2 + 5.2 = 49.6%.
0.102 + 0.102 + 0.0922 + 0.0522 + 0.01262 + . . . + 0.01262 = 0.054 + 40 0.01262 = 0.0603.
d. The combined market share of the 10 other firms is 100 − 49.6 = 50.4%. Assuming that each of
them has the same share, the share of each is 50.4/10 = 5.04%. So, the Herfindahl index for the
industry, which is the sum of the squared market shares of all the firms in the industry, is 0.1522 +
0.102 + 0.102 + 0.0922 + 0.0522 + 0.05042 + . . . + 0.05042 = 0.054 + 10 0.05042 = 0.0794.
e. There is greater competition in the scenario in Part (c) than in Part (d). The Herfindahl index in
7. a. Though News Corporation is based in Australia, it is really a global conglomerate, and a majority
of its businesses are outside of Australia. About 77 percent of its revenues are in the United
b. Due to differences in accounting standards and practices among countries, the analyst would be
concerned if he were comparing ratios of News Corporation, computed as per Australian GAAP,