Suppose that thesix firms in industry A have annual sales of 30, 20, 20, 15, 10, and5 percent of total industry sales.For the six firms in industry B, the figures are 25, 18, 16, 15, 14, and 12 percent.

b. Calculate the four-firm concentration ratio and the Herfindahl index for each industry and compare their likely competitiveness.

Industry A four-firm concentration ratio =

Industry A Herfindahl index =

Industry B four-firm concentration ratio =

Industry B Herfindahl index =