In: Economics
An industry consists of four firms with sales of $12,500,000, $13,700,000, $14,500,000 and $17,500,000 (all in thousands).
a. Calculate the Herfindahl-Hirschman index (HHI).
b. Calculate the four-firm concentration ratio (C4).
c. Based on the U.S. Department of Justice’s Merger Guidelines described in the text, do you think the Department of Justice would block a horizontal merger between two firms with sales of $12,500,000 and $13,700,000? Explain.
a) Find the market share for each firm as a percentage of total share. Then find the square of each share and add the 4 squared values. Then we get the HHI as 2540.24
Firms | Sales | Market share | Square of shares |
1 | 12500000 | 21.48 | 461.29 |
2 | 13700000 | 23.54 | 554.11 |
3 | 14500000 | 24.91 | 620.71 |
4 | 17500000 | 30.07 | 904.13 |
Total | 58200000 | 100 | 2540.24 |
b) C4 is 100 because there are only 4 firms in the market and so the sum of top 4 market shares is 100
c) In this case firm 1 and 2 merge and total share is increased to 45%. HHI is already 2540 before merger signalling a highly concentrated market and this merger raises HHI to 3551, more than 1000. This will be blocked by the DOJ because this merger makes market highly monopolistic in nature.
Firms | Sales | Market share | Square of shares |
1 | 26200000 | 45.02 | 2026.55 |
2 | 14500000 | 24.91 | 620.71 |
3 | 17500000 | 30.07 | 904.13 |
Total | 58200000 | 100 | 3551.39 |