Jean-Baptiste Say

He was also closely involved in the development of the École spéciale de commerce et d'industrie (ESCP), historically the first business school to be established.

• Name — Jean-Baptiste Say • Born — 5 January 1767 • Birthplace — Lyon, Kingdom of France • Died — 15 November 1832 • Place of death — Paris, France • Field — Political economy • School Tradition — French Liberal School • Influences — Richard Cantillon, Adam Smith, Pietro Verri • Contributions — Say's law, entrepreneurship

• Illustration — Map of Croydon, drawn by the 18-year-old Say in 1785 Say was born in Lyon. His father Jean-Etienne Say was born to a Protestant family which had moved from Nîmes to Geneva for some time in consequence of the revocation of the Edict of Nantes. Say was intended to follow a commercial career and in 1785 was sent with his brother Horace to complete his education in England. He lodged for a time in Croydon and afterwards (following a return visit to France) in Fulham. During the latter period, he was employed successively by two London-based firms of sugar merchants, James Baillie & Co and Samuel and William Hibbert. At the end of 1786, he accompanied Samuel Hibbert on a voyage to France which ended in December with Hibbert's death in Nantes. Say returned to Paris, where he found employment in the office of a life assurance company directed by Étienne Clavière. His brother Louis Auguste (1774–1840) also became an economist.

Say is well known for Say's law, or the law of markets, often controversially summarised as: • "Aggregate supply creates its own aggregate demand" • "Supply creates its own demand" Say's law is instead uncontroversially summarized as: • "Supply constitutes its own demand" • "Inherent in supply is the wherewithal for its own consumption" (direct translation from French Traité d'économie politique) The exact phrase "supply creates its own demand" was coined by John Maynard Keynes, who criticized it as in the former two, equating all four of these statements to mean the same thing. Some economists, including some advocates of Say's law who dispute this characterization as a misrepresentation, have disputed his interpretation, claiming that Say's law can actually be summarized more accurately as "production precedes consumption" and that Say was claiming that in order to consume one must produce something of value so that one can trade this (either in the form of money or barter) in order to consume later. Similar sentiments through different wordings appear in the work of John Stuart Mill (1848) and his father James Mill (1808). The Scottish classical economist James Mill restates Say's law in 1808, writing that "production of commodities creates, and is the one and universal cause which creates a market for the commodities produced". In Say's language, "products are paid for with products" (1803, p. 153) or "a glut can take place only when there are too many means of production applied to one kind of product and not enough to another" (1803, pp. 178–179). Explaining his point at length, he wrote the following: Say also wrote that it is not the abundance of money, but the abundance of other products in general that facilitates sales: Money performs but a momentary function in this double exchange; and when the transaction is finally closed, it will always be found, that one kind of commodity has been exchanged for another. Say's law may also have been culled from Ecclesiastes 5:11 – "When goods increase, they are increased that eat them: and what good is there to the owners thereof, saving the beholding of them with their eyes?" (KJV). Say's law has been considered by John Kenneth Galbraith as "the most distinguished example of the stability of economic ideas, including when they are wrong". Say's law emerged during the early period of the Industrial Revolution, at a time when the economic phenomena of increased output merged with England's cyclical inability to maintain both sales and unemployment. This led many to believe that there was a limit to the growth of production, and there may come a point when there is no means of purchasing all output generated. Say's law of markets deals with the fact that production of commodities causes income to be paid to suppliers of the components of capital, labor, and land used in producing these goods and services. The sale price of these commodities is the sum of the payments of wages, rents, and profit. Income generated during production of a commodity equals the value of that commodity. Therefore, an increase in the supply of output will result in an increase in the income necessary to generate demand for those products.

In 1793, Say married Mlle Deloche, daughter of a former lawyer.

• Illustration — Say's tomb in the Père Lachaise Cemetery in Paris In his later years, Say became subject to attacks of nervous apoplexy. He lost his wife in January 1830 and from that time his health declined. When the revolution of that year broke out, Say was named a member of the council-general of the department of the Seine, but he found it necessary to resign. Say died in Paris on 15 November 1832 and was buried in the Père Lachaise Cemetery. Rue Jean-Baptiste Say, a street in the 9th arrondissement of Paris, is named after him.

Jean-Baptiste Say worked in economics. He was employed by Collège de France and Conservatoire national des Arts et Métiers. He belonged to Royal Swedish Academy of Sciences, Russian Academy of Sciences and Warsaw Society of Friends of Learning.