JEVONS, WILLIAM STANLEY. – English philosopher and economist, born in Liverpool on 1 September 1835, died by drowning at Galley Hill, near Hastings, on 13 August 1882. He taught logic and political economy at Owen College in Manchester. He subsequently succeeded Cairnes in the chair of political economy at University College in London.
In his studies of logic, he elucidated the deductive process, understood mechanistically (Primer of logic, 1876; Pure logic and other minor works, 1890; Principles of science, 1874). He considered mathematics a form of logic and addressed the problem of probability according to the criteria of modern methodological statistics. His moral doctrine was deeply influenced by the utilitarian motives of the English philosophical tradition. His economic activity was of the greatest importance, and Theory of political economy (1871) is his most famous work. In economics he is regarded as the founder of the school that makes extensive use of the mathematical method, although he was preceded in this method by Cournot (1838) and Gossen (1854). It remains controversial, however, within what limits he anticipated the more modern tendencies of economic thought known as the theory of general equilibrium. The theory of final utility (later called marginal utility) which he advocated (1871) does not imply a new concept in relation to the classical school, but rather a more precise determination of the concept of limitation or scarcity, whose importance as an element of value had been noted by Senior. According to this theory, utility depends on the quantity of goods, and it highlights the importance of distinguishing between the utility which a good, considered as a whole, has for the individual and the utility which the individual derives from the separate doses of that good, particularly from the last dose, which is always of minimal proportion, considered either as the limit of the purchasing process or as anticipated or expected by the economic subject (final utility). Thus, in the concept of final utility, utility and scarcity become the basis of value, and it is the equivalent of Pareto’s elementary ophelimity and Walras’s scarcity. This theory conflicted with that of the classical economists, who placed the foundation of value in the cost of production.
His studies of logic subsequently assisted him in dealing with statistical problems in a series of important essays collected posthumously under the title Investigations in currency and finance (1884), concerning fluctuations in prices and monetary
questions. Other, less important posthumous writings were collected under the title Methods of social reform (1883) and contain studies concerning the State in relation to labour and public finance, and the methods of social reform.