Coase conjecture

Last updated

The Coase conjecture, developed first by Ronald Coase, is an argument in monopoly theory. The conjecture sets up a situation in which a monopolist sells a durable good to a market where resale is impossible and faces consumers who have different valuations. The conjecture proposes that a monopolist that does not know individuals' valuations will have to sell its product at a low price if the monopolist tries to separate consumers by offering different prices in different periods. This is because the monopolist is, in effect, in price competition with itself over several periods and the consumer with the highest valuation, if he is patient enough, can simply wait for the lowest price. Thus the monopolist will have to offer a competitive price in the first period which will be low. The conjecture holds only when there is an infinite time horizon, as otherwise a possible action for the monopolist would be to announce a very high price until the second to last period, and then sell at the static monopoly price in the last period. The monopolist could avoid this problem by committing to a stable linear pricing strategy or adopting other business strategies. [1]

Contents

Simple two-consumer model

Imagine there are consumers, called and with valuations of good with and respectively. The valuations are such as . The monopoly cannot directly identify individual consumers but it knows that there are 2 different valuations of a good. The good being sold is durable so that once a consumer buys it, the consumer will still have it in all subsequent periods. This means that after the monopolist has sold to all consumers, there can be no further sales. Also assume that production is such that average cost and marginal cost are both equal to zero.

The monopolist could try to charge at a in the first period and then in the second period , hence price discriminating. This will not result in consumer buying in the first period because, by waiting, she could get price equal to . To make consumer indifferent between buying in the first period or the second period, the monopolist will have to charge a price of where is a discount factor between 0 and 1. This price is such as .

Hence by waiting, forces the monopolist to compete on price with its future self.

n consumers

Imagine there are consumers with valuations ranging from to a valuation just above zero. The monopolist will want to sell to the consumer with the lowest valuation. This is because production is costless and by charging a price just above zero it still makes a profit. Hence to separate the consumers, the monopoly will charge first consumer where is the number of consumers. If the discount factor is high enough this price will be close to zero. Hence the conjecture is proved.

See also

Related Research Articles

A monopoly, as described by Irving Fisher, is a market with the "absence of competition", creating a situation where a specific person or enterprise is the only supplier of a particular thing. This contrasts with a monopsony which relates to a single entity's control of a market to purchase a good or service, and with oligopoly and duopoly which consists of a few sellers dominating a market. Monopolies are thus characterised by a lack of economic competition to produce the good or service, a lack of viable substitute goods, and the possibility of a high monopoly price well above the seller's marginal cost that leads to a high monopoly profit. The verb monopolise or monopolize refers to the process by which a company gains the ability to raise prices or exclude competitors. In economics, a monopoly is a single seller. In law, a monopoly is a business entity that has significant market power, that is, the power to charge overly high prices, which is associated with a decrease in social surplus. Although monopolies may be big businesses, size is not a characteristic of a monopoly. A small business may still have the power to raise prices in a small industry.

<span class="mw-page-title-main">Monopolistic competition</span> Imperfect competition of differentiated products that are not perfect substitutes

Monopolistic competition is a type of imperfect competition such that there are many producers competing against each other, but selling products that are differentiated from one another and hence are not perfect substitutes. In monopolistic competition, a company takes the prices charged by its rivals as given and ignores the impact of its own prices on the prices of other companies. If this happens in the presence of a coercive government, monopolistic competition will fall into government-granted monopoly. Unlike perfect competition, the company maintains spare capacity. Models of monopolistic competition are often used to model industries. Textbook examples of industries with market structures similar to monopolistic competition include restaurants, cereals, clothing, shoes, and service industries in large cities. The "founding father" of the theory of monopolistic competition is Edward Hastings Chamberlin, who wrote a pioneering book on the subject, Theory of Monopolistic Competition (1933). Joan Robinson published a book The Economics of Imperfect Competition with a comparable theme of distinguishing perfect from imperfect competition. Further work on monopolistic competition was undertaken by Dixit and Stiglitz who created the Dixit-Stiglitz model which has proved applicable used in the sub fields of international trade theory, macroeconomics and economic geography.

In economics, specifically general equilibrium theory, a perfect market, also known as an atomistic market, is defined by several idealizing conditions, collectively called perfect competition, or atomistic competition. In theoretical models where conditions of perfect competition hold, it has been demonstrated that a market will reach an equilibrium in which the quantity supplied for every product or service, including labor, equals the quantity demanded at the current price. This equilibrium would be a Pareto optimum.

<span class="mw-page-title-main">Indifference curve</span> Concept in economics

In economics, an indifference curve connects points on a graph representing different quantities of two goods, points between which a consumer is indifferent. That is, any combinations of two products indicated by the curve will provide the consumer with equal levels of utility, and the consumer has no preference for one combination or bundle of goods over a different combination on the same curve. One can also refer to each point on the indifference curve as rendering the same level of utility (satisfaction) for the consumer. In other words, an indifference curve is the locus of various points showing different combinations of two goods providing equal utility to the consumer. Utility is then a device to represent preferences rather than something from which preferences come. The main use of indifference curves is in the representation of potentially observable demand patterns for individual consumers over commodity bundles.

A two-part tariff (TPT) is a form of price discrimination wherein the price of a product or service is composed of two parts – a lump-sum fee as well as a per-unit charge. In general, such a pricing technique only occurs in partially or fully monopolistic markets. It is designed to enable the firm to capture more consumer surplus than it otherwise would in a non-discriminating pricing environment. Two-part tariffs may also exist in competitive markets when consumers are uncertain about their ultimate demand. Health club consumers, for example, may be uncertain about their level of future commitment to an exercise regimen. Two-part tariffs are easy to implement when connection or entrance fees can be charged along with a price per unit consumed.

<span class="mw-page-title-main">The Market for Lemons</span> 1970 economic paper

"The Market for 'Lemons': Quality Uncertainty and the Market Mechanism" is a widely cited seminal paper in the field of economics which explores the concept of asymmetric information in markets. The paper was written in 1970 by George Akerlof and published in the Quarterly Journal of Economics. The paper's findings have since been applied to many other types of markets. However, Akerlof's research focused solely on the market for used cars.

<span class="mw-page-title-main">Budget constraint</span> All available goods and services a customer can purchase with respect to their income

In economics, a budget constraint represents all the combinations of goods and services that a consumer may purchase given current prices within his or her given income. Consumer theory uses the concepts of a budget constraint and a preference map as tools to examine the parameters of consumer choices. Both concepts have a ready graphical representation in the two-good case. The consumer can only purchase as much as their income will allow, hence they are constrained by their budget. The equation of a budget constraint is where is the price of good X, and is the price of good Y, and m is income.

<span class="mw-page-title-main">Substitute good</span> Economics concept of goods considered interchangeable

In microeconomics, two goods are substitutes if the products could be used for the same purpose by the consumers. That is, a consumer perceives both goods as similar or comparable, so that having more of one good causes the consumer to desire less of the other good. Contrary to complementary goods and independent goods, substitute goods may replace each other in use due to changing economic conditions. An example of substitute goods is Coca-Cola and Pepsi; the interchangeable aspect of these goods is due to the similarity of the purpose they serve, i.e. fulfilling customers' desire for a soft drink. These types of substitutes can be referred to as close substitutes.

A limit price is a price, or pricing strategy, where products are sold by a supplier at a price low enough to make it unprofitable for other players to enter the market.

Rational pricing is the assumption in financial economics that asset prices – and hence asset pricing models – will reflect the arbitrage-free price of the asset as any deviation from this price will be "arbitraged away". This assumption is useful in pricing fixed income securities, particularly bonds, and is fundamental to the pricing of derivative instruments.

In economics, market power refers to the ability of a firm to influence the price at which it sells a product or service by manipulating either the supply or demand of the product or service to increase economic profit. In other words, market power occurs if a firm does not face a perfectly elastic demand curve and can set its price (P) above marginal cost (MC) without losing revenue. This indicates that the magnitude of market power is associated with the gap between P and MC at a firm's profit maximising level of output. The size of the gap, which encapsulates the firm's level of market dominance, is determined by the residual demand curve's form. A steeper reverse demand indicates higher earnings and more dominance in the market. Such propensities contradict perfectly competitive markets, where market participants have no market power, P = MC and firms earn zero economic profit. Market participants in perfectly competitive markets are consequently referred to as 'price takers', whereas market participants that exhibit market power are referred to as 'price makers' or 'price setters'.

<span class="mw-page-title-main">Marginal revenue</span> Additional total revenue generated by increasing product sales by 1 unit

Marginal revenue is a central concept in microeconomics that describes the additional total revenue generated by increasing product sales by 1 unit. Marginal revenue is the increase in revenue from the sale of one additional unit of product, i.e., the revenue from the sale of the last unit of product. It can be positive or negative. Marginal revenue is an important concept in vendor analysis. To derive the value of marginal revenue, it is required to examine the difference between the aggregate benefits a firm received from the quantity of a good and service produced last period and the current period with one extra unit increase in the rate of production. Marginal revenue is a fundamental tool for economic decision making within a firm's setting, together with marginal cost to be considered.

The Ramsey problem, or Ramsey pricing, or Ramsey–Boiteux pricing, is a second-best policy problem concerning what prices a public monopoly should charge for the various products it sells in order to maximize social welfare while earning enough revenue to cover its fixed costs.

<span class="mw-page-title-main">Durable good</span> Good that has long term use

In economics, a durable good or a hard good or consumer durable is a good that does not quickly wear out or, more specifically, one that yields utility over time rather than being completely consumed in one use. Items like bricks could be considered perfectly durable goods because they should theoretically never wear out. Highly durable goods such as refrigerators or cars usually continue to be useful for several years of use, so durable goods are typically characterized by long periods between successive purchases.

In economics, a location model or spatial model refers to any monopolistic competition model that demonstrates consumer preference for particular brands of goods and their locations. Examples of location models include Hotelling's Location Model, Salop's Circle Model, and hybrid variations.

Monopolistic competition models are used under the rubric of imperfect competition in International Economics. This model is a derivative of the monopolistic competition model that is part of basic economics. Here, it is tailored to international trade.

Competitive equilibrium is a concept of economic equilibrium, introduced by Kenneth Arrow and Gérard Debreu in 1951, appropriate for the analysis of commodity markets with flexible prices and many traders, and serving as the benchmark of efficiency in economic analysis. It relies crucially on the assumption of a competitive environment where each trader decides upon a quantity that is so small compared to the total quantity traded in the market that their individual transactions have no influence on the prices. Competitive markets are an ideal standard by which other market structures are evaluated.

The Pacman conjecture holds that durable-goods monopolists have complete market power and so can exercise perfect price discrimination, thus extracting the total surplus. This is in contrast to the Coase conjecture which holds that a durable goods monopolist has no market power, and so price is equal to the competitive market price.

In oligopoly theory, conjectural variation is the belief that one firm has an idea about the way its competitors may react if it varies its output or price. The firm forms a conjecture about the variation in the other firm's output that will accompany any change in its own output. For example, in the classic Cournot model of oligopoly, it is assumed that each firm treats the output of the other firms as given when it chooses its output. This is sometimes called the "Nash conjecture," as it underlies the standard Nash equilibrium concept. However, alternative assumptions can be made. Suppose you have two firms producing the same good, so that the industry price is determined by the combined output of the two firms. Now suppose that each firm has what is called the "Bertrand Conjecture" of −1. This means that if firm A increases its output, it conjectures that firm B will reduce its output to exactly offset firm A's increase, so that total output and hence price remains unchanged. With the Bertrand Conjecture, the firms act as if they believe that the market price is unaffected by their own output, because each firm believes that the other firm will adjust its output so that total output will be constant. At the other extreme is the Joint-Profit maximizing conjecture of +1. In this case, each firm believes that the other will imitate exactly any change in output it makes, which leads to the firms behaving like a single monopoly supplier.

In industrial organization and in particular monopoly theory, a durapolist or durable good monopolist is a producer that manipulates the durability of its product. The term was coined by antitrust scholar Barak Orbach. The concept is used to explain how durable good manufacturers overcome the durability problem of their products and persuade consumers to purchase new goods. The concept utilizes a monopolist to simplify explanations regarding product durability.

References

  1. https://ssrn.com/abstract=496175 [Orbach (2004)

Further reading

  1. Coase, Ronald. "Durability and Monopoly" in Journal of Law and Economics, vol. 15(1), pp. 143–49, 1972.
  2. Orbach, Barak. "The Durapolist Puzzle: Monopoly Power in Durable-Goods Market" in Yale Journal on Regulation, vol. 21(1), pp. 67–118, 2004.