William Petty

Sir William Petty (1623 to 1687) was an English economist, physician, scientist and philosopher, remembered above all for his theories on economics and his method of political arithmetic, the practice of describing a state through counted quantities such as land, people and wealth. Born in Romsey into a clothier family, he studied medicine, became a fellow at Brasenose College, Oxford, and served Oliver Cromwell as physician-general in Ireland. There he carried out the Down Survey, a land survey that allowed confiscated land to be distributed to Cromwell soldiers. He remained influential under Charles II and James II, was a charter member of the Royal Society, and was knighted in 1661. His quantitative approach to population and national wealth made him a forerunner of both political economy and statistics.