JEVONS, WILLIAM STANLEY

born Sept. 1, 1835, Liverpool, Eng. died Aug. 13, 1882, near Hastings, Sussex English logician and economist who expounded in his book The Theory of Political Economy (1871) the final (marginal) utility theory of value. Jevons' work, along with similar discoveries made by Karl Menger in Vienna (1871) and by Lon Walras in Switzerland (1874), marked the opening of a new period in the history of economic thought. Jevons broke off his studies of the natural sciences at University College, London, in 1854 to take a post as assayer in Sydney, Australia. There he acquired an interest in political economy and social studies. When he returned to England in 1859, he soon completed two of his most original and seminal papers, General Mathematical Theory of Political Economy (1862) and A Serious Fall in the Value of Gold (1863). In the first he outlined what subsequently came to be known as the marginal utility theory of value. This theory suggests that the utility or value to a consumer of an additional unit of a product is (at least beyond some critical quantity) inversely related to the number of units of that product he already owns. In the second he set out to measure the rise in prices in the period following the Californian and Australian gold discoveries and made one of the greatest contributions to the theory of index numbers ever published. But it was not until the publication of The Coal Question (1865), in which he called attention to the gradual exhaustion of Britain's coal supplies, that he received public recognition. In 1866 Jevons was appointed to a chair of political economy at Owens College, Manchester. He moved to University College, London, in 1876. Of his works on logic and scientific methods, the most important is his Principles of Science (1874). His other notable works include The Theory of Political Economy (1871) and The State in Relation to Labour (1882).