Determine the Herfindahl index for an industry composed of three companies one with 70% of the market, and the other two with 20 and 10 percent of the market respectively one company with 50% share of the market and 10 other equal sized firms ten equal sized firms.

Since under price leadership by the dominant firm, the companies in the industry following the leader behave as perfect competitors or price takers by always producing where the price set by the leader equals the sum of their marginal cost curves the following break even in the long run. True or False? Explain.