Editing Common good (section)

==In political economic theory==
In economics, the terms [[public good (economics)|''public good'']] and [[common good (economics)|''common good'']] have technical definitions. A public good is a good that is [[non-rivalrous]] and [[non-excludable]].{{Clarify|reason=These should be defined briefly|date=March 2024}} A common good is simply non-excludable. A simple typology illustrates the differences between various kinds of goods:

{{main|Goods#Goods classified by exclusivity and competitiveness}}
{{Good (economics)}}

The field of [[welfare economics]] studies social well-being. The approach begins with the specification of a social welfare function. The choice of a social welfare function is rooted in an ethical theory. A utilitarian social welfare function weights the well-being of each individual equally, while a Rawlsian social welfare function only considers the welfare of the least well-off individual.<ref>{{cite book|last1=Roemer|first1=John E.|title=Theories of Distributive Justice|date=1996|publisher=Harvard University Press|location=Cambridge}}</ref>

Neoclassical economic theory provides two conflicting lenses for thinking about the genesis of the common good, two distinct sets of microfoundations. On one view, the common good arises due to social gains from cooperation. Such a view might appeal to the [[Prisoner's dilemma]] to illustrate how cooperation can result in superior welfare outcomes. Moreover, a cooperative equilibrium is stable in an iterated Prisoner's dilemma that is played for an indefinite period of time. Under these conditions, an individual does best by pursuing the course of action that is also optimal for society.<ref>{{cite book|last1=Axelrod|first1=Robert|title=The Evolution of Cooperation|date=1984|publisher=Basic Books|location=New York}}</ref>

On the other hand, economic theory typically points to social gains from competition as a rationale for the use of markets. Thus, Smith described the "[[invisible hand]]," whereby the mechanism of the market converts individuals' self-interested activity into gains for society.<ref>{{cite book|last1=Smith|first1=Adam|title=The Wealth of Nations|date=1776}}</ref> This insight is formalized in the [[First theorem of welfare economics|First Theorem of Welfare Economics]]. However, economic theory also points to [[market failure]]s, including the underprovision of public goods by markets and the failure of self-interested individuals to internalize [[externalities]].<ref>{{cite book|last1=Pigou|first1=Arthur|title=Economics of Welfare|date=1920|publisher=Macmillan and Co|location=London}}</ref> Because of these factors, purely self-interested behaviour often detracts from the common good.

There is an important conceptual difference between the sense of "a" public good, or public "goods" in [[economics]], and the more generalized idea of "the public good" (in the sense of common good, public benefit, or [[public interest]]), "a shorthand signal for shared benefit at a societal level".<ref>{{cite journal |author=Morrell K |year=2009 |title=Governance and the public good |journal=[[Public Administration (journal)|Public Administration]] |volume=87 |issue=3 |pages=538–56 (quote at p 543) |doi=10.1111/j.1467-9299.2009.01756.x}}</ref><ref>{{Cite book |title=Public Administration and the Public Interest' in G.L. Wamsley and J.F.Wolf (eds), Refounding Public Administration: Modern Paradoxes. Postmodern Challenges |author=Goodsell, C.T. |date=1990 |publisher=Sage |edition=paperback |pages=96–113}}</ref><ref>{{cite journal |year=2012 |title=What is governance in the public interest? The case of the 1995 property forum in post-conflict Nicaragua |journal=[[Public Administration (journal)|Public Administration]] |volume=90 |issue=2 |pages=412–28 |doi=10.1111/j.1467-9299.2011.01977.x |vauthors=Morrell K, Harrington-Buhay N}}</ref>
In a non-economic sense, the term is often used to describe something that is useful for the public generally, such as education, although this is not a "public good" in the economic sense. However, services like education exhibit ''jointness of supply'', i.e. the situation in which the cost of supplying a good to many users is the same, or nearly the same, as supplying it to one user. Public goods also exhibit jointness of supply, albeit with no diminishment of the benefits with increased consumption.

===Social choice theory===
[[Social choice theory]] studies collective decision rules. [[Arrow's impossibility theorem|Arrow's Impossibility Theorem]], an important result in social choice theory, states that no aggregative mechanism of collective choice (restricted to ordinal inputs) can consistently transform individual preferences into a collective preference-ordering, across the universal domain of possible preference profiles, while also satisfying a set of minimal normative criteria of rationality and fairness.<ref>{{cite book|last1=Arrow|first1=Kenneth|title=Social Choice and Individual Values|date=1951|publisher=John Wiley & Sons|location=New York}}</ref> The [[Gibbard-Satterthwaite theorem]] further demonstrates that non-dictatorial voting systems are inevitably subject to strategic manipulation of outcomes.<ref>{{cite journal|last1=Gibbard|first1=Allan|title=Manipulation of voting schemes: A general result|journal=Econometrica|date=1973|volume=41|issue=4|pages=587–601|doi=10.2307/1914083|jstor=1914083}}</ref><ref>{{cite journal|last1=Satterthwaite|first1=Mark Allen|title=Strategy-proofness and Arrow's conditions: Existence and correspondence theorems for voting procedures and social welfare functions|journal=Journal of Economic Theory|date=1975|volume=10|issue=2|pages=187–217|doi=10.1016/0022-0531(75)90050-2|citeseerx=10.1.1.471.9842}}</ref>

[[William H. Riker]] articulates the standard public choice interpretation of social choice theory, arguing that Arrow's Impossibility Theorem "forces us to doubt that the content of 'social welfare' or the 'public interest' can ever be discovered by amalgamating individual value judgments. It even leads us to suspect that no such thing as the 'public interest' exists, aside from the subjective (and hence dubious) claims of self-proclaimed saviors."<ref>{{cite book|last1=Riker|first1=William|title=Liberalism Against Populism: A Confrontation Between the Theory of Democracy and the Theory of Social Choice |date=1982|publisher=Waveland Press|location=Long Grove, IL|page=137}}</ref> Thus, Riker defends a "liberal" conception of democracy, which centers on the role of constitutional checks on government. Public choice theorists have tended to share this approach. Buchanan and Tullock pursued this program in developing the field of "constitutional political economy" in their book ''[[The Calculus of Consent]]''.

More recent work in social choice theory, however, has demonstrated that Arrow's impossibility result can be obviated at little or no normative cost. [[Amartya Sen]], for instance, argues that a range of social choice mechanisms emerge unscathed given certain reasonable restrictions on the domain of admissible preference profiles.<ref>{{cite journal|last1=Sen|first1=Amartya|s2cid=16238050|title=A Possibility Theorem on Majority Decisions|journal=Econometrica|date=1966|volume=34|issue=2|pages=491–499|doi=10.2307/1909947|jstor=1909947}}</ref> In particular, requiring that preferences are single-peaked on a single dimension ensures a [[Condorcet winner]]. Moreover, many of Riker's empirical claims have been refuted.<ref>{{cite book|last1=Mackie|first1=Gerry|title=Democracy Defended|date=2004|publisher=Cambridge University Press|location=Cambridge}}</ref>

===Public choice theory===
[[Public choice theory]] (sometimes called "positive political theory") applies microeconomic methodology to the study of political science in order to explain how private interests inform political activities. Whereas welfare economics, in line with classical political economy, typically assumes a public-interest perspective on policymaking, public choice analysis adopts a private-interest perspective in order to identify how the objectives of policymakers affect policy outcomes. Public choice analysis thus diagnoses deviations from the common good resulting from activities such as [[rent-seeking]]. In ''The Logic of Collective Action'', [[Mancur Olson]] argues that public goods will tend to be underprovided due to individuals' incentives to [[free-rider problem|free-ride]].<ref>{{cite book|last1=Olson|first1=Mancur|title=The Logic of Collective Action|date=1965|publisher=Harvard University Press|location=Cambridge}}</ref> [[Anthony Downs]] provided an application of this logic to the theory of voting, identifying the [[paradox of voting]] whereby rational individuals prefer to abstain from voting, because the marginal cost exceeds the private marginal benefit.<ref>{{cite book|last1=Downs|first1=Anthony|title=An Economic Theory of Democracy|date=1957|publisher=Harper and Row|location=New York}}</ref> Downs argues further that voters generally prefer to remain uninformed due to "[[rational ignorance]]".

Public choice scholarship can have more constructive applications. For instance, [[Elinor Ostrom]]'s study of schemes for the regulation of common property resources resulted in the discovery of mechanisms for overcoming the [[tragedy of the commons]].<ref>{{cite book|last1=Ostrom|first1=Elinor|title=Governing the Commons: The Evolution of Institutions for Collective Action|date=1990|publisher=Cambridge University Press|location=Cambridge}}</ref>

In many countries of the [[Commonwealth of Nations|Commonwealth]], [[charitable organizations]] must demonstrate that they provide a [[public benefit]].<ref>Jonathan Garton (2013), ''Public Benefit in Charity Law'', OUP Oxford.</ref>