Say is easily known for Say's Law, often summarised as "Aggregate supply creates its own aggregate demand". He argued that production & low of goods around an economy automatically produces an income for a producers of a equivalent value, which would so exist as reinjected into the economy & produce plenty require to acquire the goods. So production is determined per supply of goods like than require. Unemployment of men, land or even even more resources would nin become conceivable unless it were by design, or due to a bit of rather restraint on trade.

He was as well among a number 1 to argue that money was neutral around its consequence on the economy. Money is non desired for its have sake, however for what it potty buy. An increase inside a total of money around circulation would increase the price of more goods in terms of money (stimulating inflation), but would non vary a proportional cost of goods or even a quantity produced. This idea was late developed by economic expert into a Quantity theory of money.

Say's ideas helped to inspire neoclassical economics which arose later in the 19th century. He wrote Traite d’Economique Politique.