Herfindahl-Hirschman Index (HHI) Definition, Way, and Example
What Is the Herfindahl-Hirschman Index (HHI)? The Herfindahl-Hirschman Index (HHI) is a common measure of market concentration and is used to determine market competitiveness, often pre- and post-merger and acquisition (M&A) transactions. The index measures the size of companies relative to the size of the industry they are in and the amount of competitiveness. The