Vilfredo Federico Damaso Pareto (born July 15, 1848 in Paris, France - died August 19, 1923 in Lausanne, Switzerland) made several important contributions to economics, sociology and moral philosophy, especially in the study of income distribution and in the analysis of individuals' choices. He introduced the concept of Pareto efficiency and helped develop the field of microeconomics with ideas such as indifference curves.
The son of a Genoese father and a French mother, Pareto was educated in both France and Italy, and in 1870, received an engineering degree from what is now the Polytechnic University of Turin and took employment with the Italian state railways. In 1886, he became a lecturer on economics and management at the University of Florence. In 1893, he was appointed as a lecturer in economics at the University of Lausanne in Switzerland where he remained for the rest of his life.
In 1906, he made the famous observation that 20% of the population owned 80% of the property in Italy, later generalised by Joseph M. Juran and others into the so-called Pareto principle (also termed as the 80-20 rule) and generalised further to the concept of a Pareto distribution.
The Pareto index is a measure of the inequality of income distribution.
The Pareto chart is a special type of histogram, used to view causes of a problem in order of severity from largest to smallest. It is a statistical tool that graphically demonstrates the Pareto principle or the 80-20 rule.
In his Trattato di Sociologia Generale (The Treatise on General Sociology) first published in English under the title Mind and society, he put forward the first social cycle theory in sociology.