William Stanley Jevons was an English logician, economist, and statistician. Born in Liverpool, he was the ninth child of a well-to-do family. His father was an iron merchant, and his mother was a noted banker, historian, and art collector. Jevons entered University College London to study chemistry and mathematics but left in 1853 to take a position as assayer at a new mint in Australia. After six years there, he returned to London to complete his education. Jevons devoted much of his time to what he called "combinational logic," a form of symbolic logic popular at the time. He wrote Pure Logic (1863) and also developed a logic machine now recognized as the forerunner of the modern computer. One of his first major economic works was A Serious Fall in the Value of Gold (1863), in which he virtually invented the concept of a price index so that he could compare the change in the value of gold over time. It was followed by The Coal Question (1865), an examination of the depletion of existing coal reserves that would eventually drive up the price of coal and thereby affect Britain's industrial dominance. The book was an immediate success, and the resulting "coal panic" led to the appointment of a royal commission on coal. In The Solar Period and the Price of Corn (1875), Jevons hypothesized that recurring periods of expanding and contracting business activity might somehow be linked to sunspot activity. Specifically, he argued that overall economic activity was affected by conditions in agriculture and that "the success of the harvest in any year certainly depends upon the weather.... If this weather depends in any degree upon the solar period, it follows that the harvest and the price of grain will depend more or less on the solar period, and will go through periodic fluctuations in periods of time equal to those sunspots." Jevons's idea was ridiculed at the time, but economists now credit him with recognizing the recurrent nature of the business cycle, as well as attempts to correlate business fluctuations with other phenomena. Considering the importance of agriculture at the time, and the correlation actually observed between sunspot activity and the success of the harvests, his theory cannot be completely ruled out. Jevons's last complete book, The State in Relation to Labor (1882), was an attempt to set forth a generalized treatment of economic policy. His Methods of Social Reform (1883), published after his death, spelled out his philosophy that government should help enforce contracts but interfere with their terms only if they were negotiated by parties of unequal strength. Jevons's impressive scholarly contributions were cut short by his untimely death at age 47 while swimming during a family holiday.
