William Stanley Jevons was born in Liverpool, England. He studied chemistry and botany at University College. He was chair of political economy at University College until his retirement in 1880. At the age of 46, Jevons drowned while swimming.

Carl Menger in Austria, Leon Walrus in France, and William Stanley Jevons in England separately yet simultaneously developed the theory of marginal utility to understand and to explain consumer behavior. As a result of their work, economics underwent a m ajor theoretical revolution, known as the marginal or neoclassical revolution. Jevons was very influenced by utilitarianism which is an ethical theory which states that questions of social policy and individual morality should be answered by cal culating the consequences of policies or actions on the utility of individuals. That which maximizes utility is the moral one. The early utilitarians were Jeremy Bentham, James Mill, and John Stuart Mill.

Jevons was was a strong proponent of mathmatical economics. In 1871, he stated that," our science must be mathmatical, simply because it deals with quantities." However, he was aware that mathematical economics was not an exact science. According to Jevons," Many persons entertain a prejudice against mathematical language, arising out of a confusion between the ideas of a mathematical science and an exact science...but in reality, there is no such thing as an exact science, except in a comparative se nse."

Jevons also formulated the "equation of exchange", which shows that for a consumer to be maximizing his or her utility,"the ratio of the marginal utility of each item consumed to its price must be equal."

Works by William Stanley Jevons:

• The Coal Question
  
• Investigations in Currency and Finance
  
• The Solar Period and the Price of Corn
  
• The Theory of Political Economy