Vilfredo Federico Damaso Pareto (born Wilfried Fritz Pareto; 15 July 1848 – 19 August 1923) was an Italian polymath, whose areas of interest included sociology, civil engineering, economics, political science, and philosophy. He made several important contributions to economics, particularly in the study of income distribution and in the analysis of individuals' choices. He was also responsible for popularising the use of the term elite in social analysis. He introduced the concept of Pareto efficiency and helped develop the field of microeconomics. He was also the first to claim that income follows a Pareto distribution, which is a power law probability distribution. The Pareto principle was named after him, and it was built on his observations that 80% of the wealth in Italy belonged to about 20% of the population. He also contributed to the fields of sociology and mathematics. Source: Wikipedia (en)