Session 9: Corporate Finance: Financing and Control Issues Reading 31: Mergers and Acquisitions
LOS h: Calculate the Herfendahl-Hirschman Index and evaluate the likelihood of an antitrust challenge for a given business combination.
There are 6 firms in a given industry, each with an equal market share. Suppose that 2 of the firms decide to merge. Calculate the pre- and post-merger Herfindahl-Hirschman Index, and evaluate the likelihood that the merger will be challenged on antitrust grounds.
A) |
Pre-merger HHI = 1673; Post-merger HHI = 2224; Possible. | |
B) |
Pre-merger HHI = 1673; Post-merger HHI = 2503; Virtually certain. | |
C) |
Pre-merger HHI = 1673; Post-merger HHI = 2224; Virtually certain. | |
The pre-merger HHI = 1673 = ((16.7 × 16.7 × 6)), the post-merger HHI = 2224 = ((16.7 × 16.7 × 4) + (33.3 × 33.3 × 1)). Given the 551 point change in the index, an antitrust challenge is virtually certain. |