Pareto was an economist and sociologist of Italian origin, born in Paris (1848-1923), who taught at the University of Lausanne, as well as previously did his mentor, Léon Walras. They both were part of the Lausanne School, which is considered, along with the Austrian School, as the birthplace of marginalism and neoclassical economics.
His chief works were “Course of Political Economy”, 1896-97, and “Manual of Political Economy”, 1906. Among Pareto’s contributions, we can highlight the graphical development of Edgeworth box, as well as an improvement on the way indifference curves are drawn, and studies on the personal distribution of income.
In his studies of the late nineteenth century, Pareto found some regularity in the personal distribution of income in different countries. From that regularity, he determined a series of economic and sociological conclusions, which became known afterwards as Pareto’s Laws. He also studied some regularities in businesses, where concentration was the explanation for the fact that many companies get 80% of their revenue from only 20% of its products.
Nowadays, however, he is mostly known for the Pareto optimal, a notion widely used in game theory and welfare economics.