Jean-Baptiste Say

Who Was Jean-Baptiste Say?

Jean-Baptiste Say (1767-1832) was a French classical, liberal economist and scholar. Say was born in Lyon in 1767, and had a distinguished career. He served on a government finance committee under Napoleon, taught political economy in France at the Athénée, the Conservatoire National des Arts et Metiers, and later at the College de France, where he was named as its chair of political economy.

Say's law of markets is a classical economic theory that says that production is the source of demand. According to Say's law, the ability to demand something is financed by supplying a different good.

Key Takeaways

  • Jean-Baptiste Say was a French classical liberal political economist who greatly influenced neoclassical economic thought.
  • He argued strongly in favor of competition, free trade, and lifting restraints on business.
  • Say's Law of Markets suggests that all markets will clear because there will always be demand for something if it is supplied, given the right price.
Jean-Baptiste Say

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Understanding Jean-Baptiste Say

Jean-Baptiste Say is known for his formulation of Say's Law of Markets, also referred to as his Theory of Markets, and for his book titled A Treatise On Political Economy, which was published in 1803. In addition to his famous Treatise, his other published works were the two-volume Complete Course in Practical Political Economy (in 1852) and a collection of his correspondence with fellow economist Thomas Malthus titled Letters to Mr. Malthus which discussed and debated his critics' theories of economic growth.

Say was heavily influenced by Adam Smith and the economic theories he laid out in his 1776 book Wealth of Nations. He was a big proponent of Smith’s free market theories, promoting his laissez-faire philosophies and helping to popularize them in France through his academic work and teaching.

Among others of his teachings, Say also expressed the belief that a falling price level could be a positive occurrence, if it resulted from productivity gains rather than from deflation. He also wrote about money and banking, shared his views of taxation as burdensome, and is credited by Robert L. Formaini in the Federal Reserve Bank of Dallas’s Economic Insights publication as among the first economists to discuss entrepreneurship and notions of utility, describing entrepreneurs as helpful in meeting “human wants.” Say's economist contemporaries included James Mill, Jeremy Bentham and David Ricardo.

Say's Law of Markets

Say's Law of Markets states that in order to buy goods on the market, a buyer must first have produced something of value to sell in order to obtain purchasing power (in the form of money income). This implies that the amount of effective demand for goods in an economy is a result previous acts of production, and that as a result there can never be a sustained general oversupply of goods in an economy because producing economic goods is what creates general demand for goods.

Say's Law does not claim that there can never be imbalances in supply and demand for specific goods, though Say believed that these will tend toward balances as prices adjust and that this process of price adjustment is also critical to balancing the general demand and supply of all goods. Say's law still lives on in modern neoclassical economic models which argue that if prices are flexible enough for all markets clear, then the economy in general will tend toward stability.

While Say's Law implies that the economy is in a sense self-regulating, so that production is ultimately the source of demand, it has been misinterpreted and frequently taken to mean that "supply creates its own demand." Contemporary economists John Maynard Keynes and Thomas Malthus criticized Say’s law. Later economists point to Keynes as partly or chiefly responsible for the confusion over Say's Law, characterizing Keynes's restatement of the Law as a strawman that misrepresents Say's Law in order to further Keynes's arguments at the expense of classical economics.


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Jean-Baptiste Say and U.S. Founding Fathers

Appearing in English translation, Say’s works found an admiring audience in American founding fathers Thomas Jefferson and James Madison, with whom he had an active correspondence. Madison’s letter thanking Say for sending him a copy of his Treatise reads in part, “I pray you Sir to be assured of the great value I place on your esteem … ” Jefferson was so impressed by Say that he encouraged him to move to Virginia.

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  1. Concise Encyclopedia of Economics. "Jean-Baptiste Say," Accessed April 28, 2021.

  2. Library of Economics and Liberty. "A Treatise on Political Economy," Accessed April 28, 2021.

  3. Formaini, R. Jean-Baptiste Say Foundations of France’s Free Trade Tradition. Economic Insights, 2006; 11(1): 1-4.

  4. Founders Online. "From James Madison to Jean Baptiste Say, 4 May 1816," Accessed April 28, 2021.

  5. Founders Online. "Thomas Jefferson to Jean Baptiste Say, 2 March 1815," Accessed April 28, 2021.

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