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Four-firm concentration ratio

A measure that sums the market shares of the four largest firms in an industry to assess market concentration.

Market shares

The percentage of total sales in a market that is controlled by a particular company or group of companies.

Merger

The combination of two or more companies into a single entity, which can affect market competition.

Antitrust regulators

Government agencies responsible for promoting competition and preventing monopolistic practices in the market.

Herfindahl-Hirschman Index (HHI)

A measure of market concentration calculated by summing the squares of the market shares of all firms in the industry.

Industry concentration

The extent to which a small number of firms dominate total sales in a market.

Competition

The rivalry among firms in the same industry to attract customers and increase market share.

Monopoly

A market structure where a single firm controls a significant portion of the market, limiting competition.

Market control

The ability of a firm or group of firms to influence prices and production levels in a market.

Concentration ratio approach

A method used to evaluate the level of competition in a market by analyzing the market shares of leading firms.