Jevons, William Stanley (1835-1882)

British economist who introduced the concept of marginal utility, a theory based on the measure of additional satisfaction (utility) gained by a consumer who receives one additional unit of a product or service.

Jevons's discovery of the marginal utility concept was announced in a brief paper published in 1866 and was developed further in the Theory of Political Economy (1871). His work opened up a new period in economic theorizing and was later grouped with the treatises Austrian economist Karl Menger and French economist Léon Walras, to form what became known as the ‘marginal revolution’. In his own lifetime, Jevons was better known for his textbook on logic and his applied economic studies. In The Coal Question (1865) he predicted the imminent exhaustion of Britain's coal supplies and hence the inevitable decline of Britain's industrial leadership in the world. His other quantitative studies, collected together in Investigations in Currency and Finance (1884), were concerned with seasonal and cyclical fluctuations in economic activity and included pioneering contributions to the theory of index numbers.

Jevons was born in 1835 and entered University College, London, England, at the age of 16. The collapse of his father's business in the 1847 economic crisis forced him to interrupt his studies and to accept a post as assayer at the Royal Australia Mint in Sydney, Australia. He spent five years in Australia and published a number of articles on meteorology and railway pricing. Jevons returned to England in 1859 and resumed his studies at University College. He was professor of logic and political economy at Owens College, Manchester, from 1863 and moved to London in 1876 to become Chair in Political Economy at University College until 1880. Jevons left behind notes for a number of unfinished books, including parts of Principles of Economics published by his son in 1905. Jevons's State in Relation to Labour (1882) is an important collection of essays in which he roundly condemned the dogmatic use of laissez faire economic theories opting instead for a case-by-case approach to government intervention.