1874
Léon Walras publishes Éléments d'économie politique pure (Elements of pure economics)
Along with those of Stanley Jevons and Carl Menger, this work by Walras was salient to modern economic theory. Walras was the first to attempt to model an economy to explain how prices are formed. He worked on general equilibrium, namely analysing an overall economy's state of balance taking into account the equilibrium on all its markets in goods and services. Subsequently, Alfred Marshall and in particular Kenneth Arrow and Gérard Debreu grounded this analysis in a formal mathematical framework and demonstrated the existence of general equilibrium.