Herfindahl-Hirschman Index


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Herfindahl-Hirschman Index (HHI)

A measure of market concentration, it depends on the number of firms and their size relative to the market. It is calculated by summing up the squares of market shares of each firm. For example, a market where the HHI comes to more than 1800 will be considered a concentrated market. Mergers or acquisitions that change the HHI by more than 100 points in a concentrated market may raise antitrust concerns within the Department of Justice.

Herfindahl-Hirschman Index

An index of market concentration the U.S. Department of Justice uses to determine whether a monopoly is forming. The scale goes from zero to 10,000, with 10,000 indicating that a single company controls 100% of the market share in a given industry. An HHI of less than 1000 indicates a market with little concentration, which the Justice Department prefers. Any merger or acquisition leading to an increase of more than 100 when the HHI was previously greater than 1,800 may lead to antitrust action against the company involved.
References in periodicals archive ?
Abbreviations: FQHC, Federally Qualified Health Center; HHI, Herfindahl-Hirschman Index. Statistical significance: (***) P < 0.01, (**) P < 0.05, (*) P < 0.10.
The smaller the Herfindahl-Hirschman Index, the fiercer the market competition was, so that market competition positively moderated the relationship between closeness centrality and charitable donation.
We use the herfindahl-hirschman index to measure market concentration, which allows investigating the level of competition in the product market and its impact on the competitors' operational decisions (Ranieri, 2011).
The market concentration is measured by the Herfindahl-Hirschman Index (HHI) and the four risk factors are: capital risk, credit risk, liquidity risk, and overall risk (see details in Table 1).
As a yardstick for labor market concentration, the study calculated the Herfindahl-Hirschman Index measure, similar to the application in Working Paper #24307.
Since reconductoring has affected many 150 kV lines on which wind farms are connected, an analysis of the zonal price of electricity in Sicily in last years will be carried out to demonstrate how this structural intervention, together with others [8], has allowed better integration of RES and therefore a decrease in zonal prices and in HHI index (Herfindahl-Hirschman index).
In the fifth article, the professors and researchers Carlos Fabian Ruiz of the Universidad Militar Nueva Granada (Bogota, Colombia), Luis Eduardo Ruiz of the Universidad Agustiniana (Bogota, Colombia) and Jorge Morales of the Universidad Nacional de Colombia (Bogota, Colombia), propose an alternative method of justifying the Herfindahl-Hirschman index based on ratios generated by norms on vector spaces of finite dimension.
Two common measures are the Finger-Kreinin index of export diversification (10) and the Herfindahl-Hirschman index of market concentration, both published by UNCTAD.
Herfindahl-Hirschman Index and hospital density were used to measure the level of competition.
Two approaches include (1) measuring the changes in the Herfindahl-Hirschman Index (HHI) of market concentration for three seed sub-markets and (2) an approach which determines expected changes in market prices that would result from mergers in a market featuring differentiated products, in the absence of new entry.
com, Priceonomics found that Stanford University, UCLA, MIT, Columbia University and Rice University are the most diverse as defined by the Herfindahl-Hirschman Index, which is a statistical measure of diversity in various areas.