Markkinakeskittymien

Markkinakeskittymien refers to the degree to which a market is dominated by a small number of firms. The concept is central to analyses of market structure and competition, and is used by policymakers to assess potential impediments to rivalry and efficient pricing.

Quantitative indicators include market concentration ratios such as CRn, which measure the combined share of the largest n firms, and the Herfindahl-Hirschman Index (HHI), calculated as the sum of the squares of firm market shares. Higher values indicate greater concentration. Data sources include industry reports, regulatory filings, and firm-level market shares.

Concentrated markets can enable oligopolistic or monopolistic behavior, with higher prices, reduced output, and slower innovation, though the relationship is not automatic; some concentrated markets exhibit dynamic competition and efficiencies that arise from scale.

Regulators may review mergers and acquisitions to prevent excessive concentration; competition authorities apply thresholds in antitrust investigations; policy tools include merger control, structural remedies, and, in some cases, ex-ante regulation.

Critics argue that concentration is an imperfect proxy for competition; market dynamics, product differentiation, and free entry can limit the effects of concentration; across sectors and countries, the same concentration level can imply different competitive conditions.

See also: oligopoly, competition law, market structure, CR4, HHI, antitrust policy.