Suppose that a small town has seven burger shops whose respective shares of the local hamburger market are (as percentages of all hamburgers sold): 27%, 26%, 22%, 12%, 7%, 4%, and 2%. What is the four-firm concentration ratio of the hamburger industry in this town?
The four firm concentration ratio calculates the concentration ratio of the 4 largest firms in an industry. This is done by adding the market share of the 4 largest firms