Market power

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In economics and particularly in industrial organization, market power is the ability of a firm to profitably raise the market price of a good or service over marginal cost. In perfectly competitive markets, market participants have no market power. A firm with total market power can raise prices without losing any customers to competitors. Market participants that have market power are therefore sometimes referred to as "price makers" or "price setters", while those without are sometimes called "price takers". Significant market power occurs when prices exceed marginal cost and long run average cost, so the firm makes economic profit.

A firm with market power has the ability to individually affect either the total quantity or the prevailing price in the market. Price makers face a downward-sloping demand curve, such that price increases lead to a lower quantity demanded. The decrease in supply as a result of the exercise of market power creates an economic deadweight loss which is often viewed as socially undesirable. As a result, many countries have antitrust or other legislation intended to limit the ability of firms to accrue market power. Such legislation often regulates mergers and sometimes introduces a judicial power to compel divestiture.

A firm usually has market power by virtue of controlling a large portion of the market. In extreme cases—monopoly and monopsony—the firm controls the entire market. However, market size alone is not the only indicator of market power. Highly concentrated markets may be contestable if there are no barriers to entry or exit, limiting the incumbent firm's ability to raise its price above competitive levels.

Market power gives firms the ability to engage in unilateral anti-competitive behavior.[1] Some of the behaviours that firms with market power are accused of engaging in include predatory pricing, product tying, and creation of overcapacity or other barriers to entry. Unilateral market power is one of the most common causes of prices being higher than the competitive equilibrium. Market power has been seen to exert more upward pressure on prices than do variations in the quantity of sellers present in the market. This is due to effects relating to Nash equilibria and profitable deviations that can be made by raising prices.[2]

If no individual participant in the market has significant market power, then anti-competitive behavior can take place only through collusion, or the exercise of a group of participants' collective market power.

The Lerner index and Herfindahl index may be used to measure market power.


When several firms control a significant share of market sales, the resulting market structure is called an oligopoly or oligopsony. An oligopoly may engage in collusion, either tacit or overt, and thereby exercise market power. A group of firms that explicitly agree to affect market price or output is called a cartel.

Monopoly power[edit]

Monopoly power is an example of market failure which occurs when one or more of the participants has the ability to influence the price or other outcomes in some general or specialized market. The most commonly discussed form of market power is that of a monopoly, but other forms such as monopsony, and more moderate versions of these two extremes, exist.

A well-known example of monopolistic market power is Microsoft's market share in PC operating systems. The United States v. Microsoft case dealt with an allegation that Microsoft illegally exercised its market power by bundling its web browser with its operating system. In this respect, the notion of dominance and dominant position in EU Antitrust Law is a strictly related aspect.[3]


A monopoly can raise prices and retain customers because the monopoly has no competitors. If a customer has no other place to go to obtain the goods or services, they either pay the increased price or do without.[4] Thus the key to market power is to preclude competition through high barriers of entry. Barriers to entry that are significant sources of market power are control of scarce resources, increasing returns to scale, technological superiority and government created barriers to entry.[5] OPEC is an example of an organization that has market power due to control over scarce resources — oil. Increasing returns to scale are another important source of market power. Firms experiencing increasing returns to scale are also experiencing decreasing average total costs.[5] Firms in such industries become more profitable with size.[5] Therefore over time the industry is dominated by a few large firms. This dominance makes it difficult for start up firms to succeed.[5] Firms like power companies, cable television companies and wireless communication companies with large start up costs fall within this category. A company wishing to enter such industries must have the financial ability to spend millions of dollars before starting operations and generating any revenue.[6] Similarly established firms also have a competitive advantage over new firms. An established firm threatened by a new competitor can lower prices to drive out the competition. Microsoft is a firm that has substantial pricing or market power due to technological superiority in its design and production processes.[5] Finally government created barriers to entry can be a source of market power. A prime example are patents granted to pharmaceutical companies. These patents give the drug companies a virtual monopoly in the protected product for the term of the patent.


Concentration ratios are the most common measures of market power.[7] The four-firm concentration ratio measures the percentage of total industry output attributable to the top four companies. For monopolies, the four firm ratio is 100 per cent while the ratio is zero for perfect competition.[8] The four firm concentration domestic (U.S) ratios for cigarettes is 93%; for automobiles, 84% and for beer, 85%.[9]

Another measure of concentration is the Herfindahl-Hirschman Index (HHI) which is calculated by "summing the squares of the percentage market shares of all participants in the market".[9] The HHI index for perfect competition is zero; for monopoly, 10,000.

U.S. courts almost never consider a firm to possess market power if it has a market share of less than 50 percent.[10]

A market with an HHI of less than 1,500 is considered to be a competitive marketplace, an HHI of 1,500 to 2,500 to be a moderately concentrated marketplace, and an HHI of 2,500 or greater to be a highly concentrated marketplace. But there is a few limitation for the HHI Index. The majority  limitation of it is that the firm in specific areas of the country has a monopoly within the specific marketplace in which it does business.[11] For example, after merger of Sprint and T-Mobile, it has increased hundreds HHI in this country, but as for it is in certain geographical areas, so the HHI value will more than 1000 in the actual market.

Elasticity of demand[edit]

Market power is the ability to raise price above marginal cost (MC) and earn a positive economic profit.[12] The degree to which a firm can raise price (P) above marginal cost depends on the shape of the demand curve at the profit maximizing output.[12] That is, elasticity is the critical factor in determining market power. The relationship between market power and the price elasticity of demand (PED) can be summarized by the equation:

PED is negative and moreover less than –1, which is to say that demand is elastic at the monopolist’s optimum point, since a point at which demand is inelastic cannot be the optimum – marginally increasing price and thus lowering output would both increase revenue and decrease cost. Hence the ratio P/MC is always greater than one. The higher the P/MC ratio, the more market power the firm possesses. As PED increases in magnitude, the P/MC ratio approaches one, and market power approaches zero.[13] The equation is derived from the monopolist pricing rule:

Mergers of competing buyers[edit]

Another significant method to enhance the market power of buyers is the mergers of competing buyers, sometimes which is called "monopsony power".[14] On the Delphic declaration in the 1992 Guidelines, we need to hire a third agency to evaluate whether the buyers are eligible to improve the market buyer power. The issue of buyer power has always been one of the most fundamental issues in antitrust case law in the history. Therefore, The merger policy has established a series of standards to measure whether the agencies will generate the risk of excessive buyer power when it increases market power.[improper synthesis?]

Another possible case is that the merger of competing buyers may reduce competition in a way that is harmful to the seller.[14] So the agency has claimed the effect on sellers arising from a lessening of competition. Which is, mergers of buyers can not increase the market power of the buyer, but it may still cause the merged company to lower prices—a classical exercise of monopsony power.[15] For example, a merger of Tyson Foods and Hillshire Farms could enable the merged company to reduce the prices paid to pig farmers for animals used to make sausage.[16]

So in a short-run reduction of purchasing number, the agencies do not treat it as best indicator of whether it can enhance the buyer's market power. Also, these agencies did not evaluate the competitive effect of merger among competitors with the impact of downstream markets sold by merger.

For an example by United States Department of Justice, Merging Firms A and B are the only two buyers in the relevant geographic market for an agricultural product.[14] Their merger will enhance buyer power and depress the price paid to farmers for this product, causing a transfer of wealth from farmers to the merged firm and inefficiently reducing supply. These effects can arise even if the merger will not lead to any increase in the price charged by the merged firm for its output.

International relations[edit]

Large markets are a source of power in international politics, as market size provides states with the power to shape regulations and standards globally.[17] The creation of the Common Market in Europe has been seen as a way that European countries increased their power.[18]

Nobel Memorial Prize[edit]

Jean Tirole was awarded the 2014 Nobel Memorial Prize in Economic Sciences for his analysis of market power and economic regulation.

See also[edit]


  1. ^ Vatiero Massimiliano (2010). "The Ordoliberal notion of market power: an institutionalist reassessment". European Competition Journal. 6 (3): 689–707. doi:10.5235/ecj.v6n3.689. S2CID 154973650.
  2. ^ Davis D.D. (2008) Market Power and Collusion in Laboratory Markets. In: Palgrave Macmillan (eds) The New Palgrave Dictionary of Economics. Palgrave Macmillan, London
  3. ^ Vatiero M. (2009), "An Institutionalist Explanation of Market Dominances". World Competition. Law and Economics Review, 32(2):221–226.
  4. ^ If the power company raised rates the customer either pays the increase or does without power.
  5. ^ a b c d e Krugman & Wells, Microeconomics 2d ed. (Worth 2009)
  6. ^ Often such natural monopolies will also have the benefit of government granted monopolies.
  7. ^ Samuelson & Nordhaus, Microeconomics, 17th ed. (McGraw-Hill 2001) at 183–184.
  8. ^ Samuelson & Nordhaus, Microeconomics, 17th ed. (McGraw-Hill 2001) at 183.
  9. ^ a b Samuelson & Nordhaus, Microeconomics, 17th ed. (McGraw-Hill 2001) at 184.
  10. ^ J. Gregory Sidak & Hal J. Singer, Überregulation Without Economics: The World Trade Organization’s Decision in the U.S.-Mexico Arbitration on Telecommunications Services, General Agreement on Trade in Services, GATS, 57 FED. COMM. L.J. 1, 34 (2004),
  11. ^ Carstensen, Peter C. (2011–2012). "Buyer Power and the Horizontal Merger Guidelines: Minor Progress on an Important Issue". University of Pennsylvania Journal of Business Law. 14: 775.
  12. ^ a b Perloff, J: Microeconomics Theory & Applications with Calculus page 369. Pearson 2008.
  13. ^ Perloff, J: Microeconomics Theory & Applications with Calculus Pearson 2008.
  14. ^ a b c "Horizontal Merger Guidelines (08/19/2010)". US Department of Justice. 2015-06-25. Retrieved 2020-11-01.
  15. ^ Hemphill, C. Scott; Rose, Nancy L. (2017–2018). "Mergers That Harm Sellers". Yale Law Journal. 127: 2078.
  16. ^ "United States v. United Foods, Inc. (2001)", Encyclopedia of the First Amendment, CQ Press, 2009, doi:10.4135/9781604265774.n1357, ISBN 978-0-87289-311-5
  17. ^ Kalyanpur, Nikhil; Newman, Abraham L. (2019). "Mobilizing Market Power: Jurisdictional Expansion as Economic Statecraft". International Organization. 73 (1): 1–34. doi:10.1017/S0020818318000334. ISSN 0020-8183.
  18. ^ Damro, Chad (2012). "Market power Europe". Journal of European Public Policy. 19 (5): 682–699. doi:10.1080/13501763.2011.646779. hdl:20.500.11820/437af490-aca0-41b5-a9c2-45f18e5eb368. S2CID 154427256.

Further references[edit]

  • Brickley, Smith and Zimmerman (13 October 2008). "7". Managerial Economics and Organizational Architecture (3rd ed.). McGraw-Hill. ISBN 978-0073375823.
  • "The Theory of Industrial Organization", Tirole, MIT Press 1988