Léon Walras, a French economist (1834-1910), is considered, along with W. S. Jevons and Carl Menger, a co-founder of marginalism and theory of utility. He is regarded as the founder, along with Pareto, of the Lausanne School. On his “Elements of Pure Economics”, 1874, Walras made his major contribution to economics, general equilibrium theory, on which all demands are interrelated into a coherent set of relationships.
This general equilibrium was reached by means of a “tâtonnement”, changes in price that would gradually approximate supply and demand until a steady statewas reached. A few decades later, Alfred Marshall would present a different general equilibrium theory, on which the steady state would be reached by means of changes in quantities.