Excludability

Last updated May 20, 2024

In economics, excludability is the degree to which a good, service or resource can be limited to only paying customers, or conversely, the degree to which a supplier, producer or other managing body (e.g. a government) can prevent consumption of a good. In economics, a good, service or resource is broadly assigned two fundamental characteristics; a degree of excludability and a degree of rivalry.

Excludability was originally proposed in 1954 by American economist Paul Samuelson where he formalised the concept now known as public goods, i.e. goods that are both non-rivalrous and non-excludable.^[1] Samuelson additionally highlighted the market failure of the free-rider problem that can occur with non-excludable goods. Samuelson's theory of good classification was then further expanded upon by Richard Musgrave in 1959, Garrett Hardin in 1968 who expanded upon another key market inefficiency of non-excludeable goods; the tragedy of the commons.^[2]

Excludability is not an inherent characteristic of a good. Therefore, excludability was further expanded upon by Elinor Ostrom in 1990 to be a continuous characteristic, as opposed to the discrete characteristic proposed by Samuelson (who presented excludability as either being present or absent).^[1] Ostrom's theory proposed that excludability can be placed on a scale that would range from fully excludable (i.e. a good that could theoretically fully exclude non-paying consumers) to fully non-excludeable (a good that cannot exclude non-paying customers at all).^[3] This scale allows producers and providers more in-depth information that can then be used to generate more efficient price equations (for public goods in particular), that would then maximize benefits and positive externalities for all consumers of the good^[4]

Definition matrix

Examples

Excludable

The easiest characteristic of an excludable good is that the producer, supplier or managing body of the good, service or resource have been able to restrict consumption to only paying consumers, and excluded non-paying consumers. If a good has a price attached to it, whether it's a one time payment like in the case of clothing or cars, or an ongoing payment like a subscription fee for a magazine or a per-use fee like in the case of public transport, it can be considered to be excludable to some extent.

A common example is a movie in a cinema. Paying customers are given a ticket that would entitle them to a single showing of the movie, and this is checked and ensured by ushers, security and other employees of the cinema. This means that a viewing of the movie is excludable and non-paying consumers are unable to experience the movie.

Semi-Excludable

Ranging between being fully excludable and non-excludable is a continuous scale of excludability that Ostrom developed.^[3] Within this scale are goods that either attempt to be excludable but cannot effective or efficiently enforce this excludability. One example concerns many forms of information such as music, movies, e-books and computer software. All of these goods have some price or payment involved in their consumption, but are also susceptible to piracy and copyright infringements. This can result in many non-paying consumers being able to experience and benefit from the goods of a single purchase or payment.

Non-Excludable

A good, service or resource that is unable to prevent or exclude non-paying consumers from experiencing or using it can be considered non-excludable. An architecturally pleasing building, such as Tower Bridge, creates an aesthetic non-excludable good, which can be enjoyed by anyone who happens to look at it. It is difficult to prevent people from gaining this benefit. A lighthouse acts as a navigation aid to ships at sea in a manner that is non-excludable since any ship out at sea can benefit from it.

Implications and inefficiency

Public goods will generally be underproduced and undersupplied in the absence of government subsidies, relative to a socially optimal level. This is because potential producers will not be able to realize a profit (since the good can be obtained for free) sufficient to justify the costs of production. In this way the provision of non-excludable goods is a classic example of a positive externality which leads to inefficiency. In extreme cases this can result in the good not being produced at all, or it being necessary for the government to organize its production and distribution.

A classic example of the inefficiency caused by non-excludability is the tragedy of the commons (which Hardin, the author, later corrected to the 'tragedy of the unmanaged commons' because it is based on the notion of an entirely rule-less resource) where a shared, non-excludable, resource becomes subject to over-use and over-consumption, which destroys the resource in the process.

Economic theory

Brito and Oakland (1980) study the private, profit-maximizing provision of excludable public goods in a formal economic model.^[5] They take into account that the agents have private information about their valuations of the public good. Yet, Brito and Oakland only consider posted-price mechanisms, i.e. there are ad-hoc constraints on the class of contracts. Also taking distribution costs and congestion effects into account, Schmitz (1997) studies a related problem, but he allows for general mechanisms.^[6] Moreover, he also characterizes the second-best allocation rule, which is welfare-maximizing under the constraint of nonnegative profits. Using the incomplete contracts theory, Francesconi and Muthoo (2011) explore whether public or private ownership is more desirable when non-contractible investments have to be made in order to provide a (partly) excludable public good.^[7]

Related Research Articles

The tragedy of the commons is a metaphoric label for a concept that is widely discussed, and criticised, in economics, ecology and other sciences. According to the concept, should a number of people enjoy unfettered access to a finite, valuable resource such as a pasture, they will tend to over-use it, and may end up destroying its value altogether. Even if some users exercised voluntary restraint, the other users would merely supplant them, the predictable result being a tragedy for all.

Environmental economics is a sub-field of economics concerned with environmental issues. It has become a widely studied subject due to growing environmental concerns in the twenty-first century. Environmental economics "undertakes theoretical or empirical studies of the economic effects of national or local environmental policies around the world. ... Particular issues include the costs and benefits of alternative environmental policies to deal with air pollution, water quality, toxic substances, solid waste, and global warming."

In economics, the free-rider problem is a type of market failure that occurs when those who benefit from resources, public goods and common pool resources do not pay for them or under-pay. Examples of such goods are public roads or public libraries or services or other goods of a communal nature. Free riders are a problem for common pool resources because they may overuse it by not paying for the good. Consequently, the common pool resource may be under-produced, overused, or degraded. Additionally, it has been shown that despite evidence that people tend to be cooperative by nature, the presence of free-riders causes cooperation to deteriorate, perpetuating the free-rider problem.

<span class="mw-page-title-main">Externality</span> In economics, an imposed cost or benefit

In economics, an externality or external cost is an indirect cost or benefit to an uninvolved third party that arises as an effect of another party's activity. Externalities can be considered as unpriced components that are involved in either consumer or producer market transactions. Air pollution from motor vehicles is one example. The cost of air pollution to society is not paid by either the producers or users of motorized transport to the rest of society. Water pollution from mills and factories is another example. All (water) consumers are made worse off by pollution but are not compensated by the market for this damage. A positive externality is when an individual's consumption in a market increases the well-being of others, but the individual does not charge the third party for the benefit. The third party is essentially getting a free product. An example of this might be the apartment above a bakery receiving some free heat in winter. The people who live in the apartment do not compensate the bakery for this benefit.

In neoclassical economics, market failure is a situation in which the allocation of goods and services by a free market is not Pareto efficient, often leading to a net loss of economic value. The first known use of the term by economists was in 1958, but the concept has been traced back to the Victorian philosopher Henry Sidgwick. Market failures are often associated with public goods, time-inconsistent preferences, information asymmetries, non-competitive markets, principal–agent problems, or externalities.

In economics, a public good is a good that is both non-excludable and non-rivalrous. Use by one person neither prevents access by other people, nor does it reduce availability to others. Therefore, the good can be used simultaneously by more than one person. This is in contrast to a common good, such as wild fish stocks in the ocean, which is non-excludable but rivalrous to a certain degree. If too many fish were harvested, the stocks would deplete, limiting the access of fish for others. A public good must be valuable to more than one user, otherwise, its simultaneous availability to more than one person would be economically irrelevant.

Information goods are commodities that provide value to consumers as a result of the information it contains and refers to any good or service that can be digitalized. Examples of information goods includes books, journals, computer software, music and videos. Information goods can be copied, shared, resold or rented. Information goods are durable and thus, will not be destroyed through consumption. As information goods have distinct characteristics as they are experience goods, have returns to scale and are non-rivalrous, the laws of supply and demand that depend on the scarcity of products do not frequently apply to information goods. As a result, the buying and selling of information goods differs from ordinary goods. Information goods are goods whose unit production costs are negligible compared to their amortized development costs. Well-informed companies have development costs that increase with product quality, but their unit cost is zero. Once an information commodity has been developed, other units can be produced and distributed at almost zero cost. For example, allow downloads over the Internet. Conversely, for industrial goods, the unit cost of production and distribution usually dominates. Firms with an industrial advantage do not incur any development costs, but unit costs increase as product quality improves.

The theory of consumer choice is the branch of microeconomics that relates preferences to consumption expenditures and to consumer demand curves. It analyzes how consumers maximize the desirability of their consumption, by maximizing utility subject to a consumer budget constraint. Factors influencing consumers' evaluation of the utility of goods include: income level, cultural factors, product information and physio-psychological factors.

Welfare economics is a field of economics that applies microeconomic techniques to evaluate the overall well-being (welfare) of a society. This evaluation is typically done at the economy-wide level, and attempts to assess the distribution of resources and opportunities among members of society.

Allocative efficiency is a state of the economy in which production is aligned with the preferences of consumers and producers; in particular, the set of outputs is chosen so as to maximize the social welfare of society. This is achieved if every produced good or service has a marginal benefit equal to the marginal cost of production.

In economics, goods are items that satisfy human wants and provide utility, for example, to a consumer making a purchase of a satisfying product. A common distinction is made between goods which are transferable, and services, which are not transferable.

In economics, a good is said to be rivalrous or a rival if its consumption by one consumer prevents simultaneous consumption by other consumers, or if consumption by one party reduces the ability of another party to consume it. A good is considered non-rivalrous or non-rival if, for any level of production, the cost of providing it to a marginal (additional) individual is zero. A good is "anti-rivalrous" and "inclusive" if each person benefits more when other people consume it.

Erik Lindahl was a Swedish economist. He was professor of economics at Uppsala University 1942–58 and in 1956–59 he was the President of the International Economic Association. He was an also an advisor to the Swedish government and the central bank, and in 1943 was elected as a member of the Royal Swedish Academy of Sciences. Lindahl posed the question of financing public goods in accordance with individual benefits. The quantity of the public good satisfies the requirement that the aggregate marginal benefit equals the marginal cost of providing the good.

Club goods are a type of good in economics, sometimes classified as a subtype of public goods that are excludable but non-rivalrous, at least until reaching a point where congestion occurs. Often these goods exhibit high excludability, but at the same time low rivalry in consumption. Thus, club goods have essentially zero marginal costs and are generally provided by what is commonly known as natural monopolies. Furthermore, club goods have artificial scarcity. Club theory is the area of economics that studies these goods. One of the most famous provisions was published by Buchanan in 1965 "An Economic Theory of Clubs," in which he addresses the question of how the size of the group influences the voluntary provision of a public good and more fundamentally provides a theoretical structure of communal or collective ownership-consumption arrangements.

In economics, a common-pool resource (CPR) is a type of good consisting of a natural or human-made resource system, whose size or characteristics makes it costly, but not impossible, to exclude potential beneficiaries from obtaining benefits from its use. Unlike pure public goods, common pool resources face problems of congestion or overuse, because they are subtractable. A common-pool resource typically consists of a core resource, which defines the stock variable, while providing a limited quantity of extractable fringe units, which defines the flow variable. While the core resource is to be protected or nurtured in order to allow for its continuous exploitation, the fringe units can be harvested or consumed.

A Lindahl tax is a form of taxation conceived by Erik Lindahl in which individuals pay for public goods according to their marginal benefits. In other words, they pay according to the amount of satisfaction or utility they derive from the consumption of an additional unit of the public good. Lindahl taxation is designed to maximize efficiency for each individual and provide the optimal level of a public good.

Common goods are defined in economics as goods that are rivalrous and non-excludable. Thus, they constitute one of the four main types based on the criteria:

The Commonize Costs–Privatize Profits Game is a concept developed by the ecologist Garrett Hardin to describe a "game" widely played in matters of resource allocation. The concept is Hardin's interpretation of the closely related phenomenon known as the tragedy of the commons, and is referred to in political discourse as "privatizing profits and socializing losses."

The commodification of water refers to the process of transforming water, especially freshwater, from a public good into a tradable commodity also known as an economic good. This transformation introduces water to previously unencumbered market forces in the hope of being managed more efficiently as a resource. The commodification of water has increased significantly during the 20th century in parallel with fears over water scarcity and environmental degradation.

This glossary of economics is a list of definitions of terms and concepts used in economics, its sub-disciplines, and related fields.

References

1 2 Samuelson, Paul (Nov 1954). "The Pure Theory of Public Expenditure". The Review of Economics and Statistics. 36 (4): 387–389. doi:10.2307/1925895. JSTOR 1925895.
↑ Hardin, Garrett (1968-12-13). "The Tragedy of the Commons". Science. 162 (3859): 1243–1248. Bibcode:1968Sci...162.1243H. doi:10.1126/science.162.3859.1243. ISSN 0036-8075. PMID 5699198.
1 2 Ostrom, Elinor (2010-06-01). "Beyond Markets and States: Polycentric Governance of Complex Economic Systems". American Economic Review. 100 (3): 641–672. doi:10.1257/aer.100.3.641. ISSN 0002-8282. S2CID 2371158.
↑ Blomquist, Sören; Christiansen, Vidar (2005-01-01). "The Role of Prices for Excludable Public Goods". International Tax and Public Finance. 12 (1): 61–79. doi:10.1007/s10797-005-6395-z. hdl: 10419/75780 . ISSN 1573-6970. S2CID 16804457.
↑ Brito, Dagobert L.; Oakland, William H. (1980). "On the Monopolistic Provision of Excludable Public Goods". The American Economic Review. 70 (4): 691–704. JSTOR 1803565.
↑ Schmitz, Patrick W. (1997). "Monopolistic Provision of Excludable Public Goods under Private Information". Public Finance. 52 (1): 89–101.
↑ Francesconi, Marco; Muthoo, Abhinay (2011). "Control Rights in Complex Partnerships" (PDF). Journal of the European Economic Association. 9 (3): 551–589. doi:10.1111/j.1542-4774.2011.01017.x. ISSN 1542-4766.