Data Concerning the Four-Firm Concentration Ratios for U

Multiple Choice

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