Marie-Esprit-Léon Walras (December 16, 1834 in Évreux, France - January 5, 1910 in Clarens, near Montreux, Switzerland) was a French economist, considered by Joseph Schumpeter as "the greatest of all economists". He was a mathematical economist associated with the creation of the general equilibrium theory.
Walras was the son of French economist Auguste Walras. Auguste was a school administrator and not a professional economist, yet his economic thinking had a profound effect on his son. He found the value of goods by setting their scarcity relative to human wants.
Walras also inherited his father's interest in social reform. Much like the Fabians, Walras called for the nationalization of land, believing that land’s value would always increase and that rents from that land would be sufficient to support the nation without taxes.
Another of Walras’ influences was Augustin Cournot, a former schoolmate. Through Cournot, Walras came under the influence of French Rationalism and was introduced to the use of mathematics in economics. Cournot created functional relationships where “quantities are related to demand prices and costs.” He also created the downward sloping demand curve.
Although Walras came to be regarded as one of the three leaders of the marginalist revolution, he was not familiar with the two other leading figures of marginalism, William Stanley Jevons and Carl Menger, and developed his theories independently.
In 1874 and 1877 Walras published Elements of Pure Economics, a work that led him to be considered the father of the general equilibrium theory. The problem that Walras set out to solve was one presented by Cournot, that even though it could be demonstrated how individual markets behaved, it was still unknown how goods interacted with each other to effect supplies and demands.
Walras created a system of simultaneous equations in an attempt to solve Cournot’s problem. He recognized that while his system may be correct, the number of unknowns combined with the lack of information made it unsolvable.
Professor at the University of Lausanne, Switzerland, Walras is credited for having founded what subsequently became known, under direction of his Italian disciple, the economist and sociologist Vilfredo Pareto, as the Lausanne school of economics.
Because for a long time most of Walras' publications were only available in French, only a relatively small section of the economics profession really became familiar with his work. This changed in the 1950s, largely due to the work of William Jaffé, the translator of Walras' main works, and the editor of his Complete Correspondence (1965).