Data concerning the four-firm concentration ratios for U.S. manufacturing industries indicate that
A) very few oligopolies exist in the real world but the oligopoly model is still useful because it tells us something about firm behavior
B) oligopolies are the second most prevalent market structure, monopoly being the first
C) the four leading firms usually have less than 10 percent of industry sales
D) the ratios are considerably less than the ratios in Canada and Western Europe
E) oligopolies are very common

Question

Quizplus · Accepted Answer

The four-firm concentration ratios, which measure the total market share of the four largest firms in an industry, often reveal high levels of concentration, indicating that oligopolies are indeed very common in U.S. manufacturing industries. This contradicts the notion that oligopolies are rare or that the leading firms usually have a small market share.

Data Concerning the Four-Firm Concentration Ratios for U