Monopolmakt

Monopolmakt is a term used to describe the market power held by a monopolist, referring to its ability to influence prices, output, and terms of trade due to the absence of close substitutes and high barriers to entry. In economic theory, monopoly power is often measured by indicators such as the Lerner index (price minus marginal cost divided by price) or by market concentration metrics like the Herfindahl-Hirschman Index.

Key features of monopolmakt include a single or dominant supplier in a market, high barriers to entry (economies of scale, legal restrictions, network effects, or control of essential inputs), and the ability to exercise strategic behavior such as price discrimination, output limitation, or exclusive contracts. Market power is not merely about setting prices; it also shapes product availability, innovation incentives, and contractual terms.

The presence of monopolmakt can lead to welfare losses for consumers, including higher prices and reduced output relative to a competitive benchmark. Some arguments point to potential efficiency gains in certain natural monopolies, where single provision may be more economical due to high fixed costs or network effects. Nevertheless, the overall effect on social welfare depends on regulation, competition policy, and how benefits and costs are distributed.

Policy responses aim to limit or manage monopolmakt through antitrust regulation, price controls, public provision, or measures to promote entry and competition. In modern economies, concerns about market power extend beyond traditional firms to digital platforms and other sectors where scale and network effects create dominant positions. See also Monopoly, Market power, Antitrust law, Regulation, Natural monopoly.