# Utility

Utility, or usefulness, is the ability of something to satisfy needs or wants. Utility is an important concept in economics and game theory, because it represents satisfaction experienced by the consumer of a good.

## Quotes

* Utility then is not the measure of exchangeable value, although it is absolutely essential to it.
** David Ricardo, The Principles of Political Economy and Taxation (1821) (Third Edition), Chapter I, Section I, On Value, p. 5.
* Possessing utility, commodities derive their exchangeable value from two sources: from their scarcity, and from the quantity of labour required to obtain them.
** David Ricardo, The Principles of Political Economy and Taxation (1821) (Third Edition), Chapter I, Section I, On Value, p. 5.
* One of the most important axioms is, that as the quantity of any commodity, for instance, plain food, which a man has to consume, increases, so the utility or benefit derived from the last portion used decreases in degree. The decrease in enjoyment between the beginning and the end of a meal may be taken as an example.
** William Stanley Jevons. Letter to his brother (1 June 1860), published in Letters and Journal of W. Stanley Jevons (1886), edited by Harriet A. Jevons, his wife, p. 151 - 152.
* Repeated reflection and inquiry have led me to the somewhat novel opinion, that value depends entirely upon utility.
** William Stanley Jevons, The Theory of Political Economy (1871), Chapter I, Introduction, p. 37.
* The calculus of utility aims at supplying the ordinary wants of man at the least cost of labour.
** William Stanley Jevons, The Theory of Political Economy (1871), Chapter I, Introduction, p. 53.
* My principal work now lies in tracing out the exact nature and conditions of utility. It seems strange indeed that economists have not bestowed more minute attention on a subject which doubtless furnishes the true key to the problems of economics.
** William Stanley Jevons, The Theory of Political Economy (1871), Chapter III, Theory of Utility, p. 65.
* The difficulties of economics are mainly the difficulties of conceiving clearly and fully the conditions of utility.
** William Stanley Jevons, The Theory of Political Economy (1871), Chapter III, Theory of Utility, p. 82.
* The general theory of economic equilibrium was strengthened and made effective as an organon of thought by two powerful subsidiary conceptions — the Margin and Substitution. The notion of the Margin was extended beyond [Utility]] to describe the equilibrium point in given conditions of any economic factor which can be regarded as capable of small variations about a given value,or in its functional relation to a given value.
** John Maynard Keynes, Essays In Biography (1933); Chapter. "Alfred Marshall," p. 223.
* Thus public works even of doubtful utility may pay for themselves over and over again at a time of severe unemployment, if only from the diminished cost of relief expenditure.
** John Maynard Keynes, The General Theory of Employment, Interest and Money (1936) , Book 3, chapter 10, Section 5, p. 12.
* No human being has the faculty of originally creating matter, which is more than nature itself can do. But any one may avail himself of the agents offered him by nature, to invest matter with utility.
** Jean-Baptiste Say, A Treatise On Political Economy (Fourth Edition) (1832), Book I, On Production, Chapter II, p. 65.
* A man who applies his labour to the investing of objects with value by the creation of utility of some sort, can not expect such a value to be appreciated and paid for, unless where other men have the means of purchasing it. Now, of what do these means consist? Of other values of other products, likewise the fruits of industry, capital, and land. Which leads us to a conclusion that may at first appear paradoxical, namely, that it is production which opens a demand for products.
** Jean-Baptiste Say, A Treatise On Political Economy (Fourth Edition) (1832), Book I, On Production, Chapter XV, p. 133 (See also: Say's Law).
* Morality has always had a difficult time of it; utility and legality even begrudge the fact of its existence.
** Friedrich Schlegel, Philosophical Fragments, P. Firchow, trans. (1991), “Athenaeum Fragments,” § 373

## See also

* Economics
* Efficiency
* Utilitarianism