Vilfredo Federico Damaso Pareto ( , , , ; born Wilfried Fritz Pareto; 15 July 1848 – 19 August 1923) was an Italian polymath (civil engineer, sociologist, economist, political scientist, and philosopher). 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 discover 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. According to the mathematician Benoit Mandelbrot and Richard L. Hudson: Biography Pareto was born of an exiled noble Genoese family in 1848 in Paris, the centre of the popular revolutions of that year. His father, Raffaele Pareto (1812–1882), was an Italian civil engineer and Ligurian marquis who had left Italy much as Giuseppe Mazzini and other Italian nationalists had. His mother, Marie Metenier, was a French woman. Enthusiastic about the revolutions of 1848 in the German states, his parents named him Wilfried Fritz, which became Vilfredo Federico upon his family's move back to Italy in 1858. In his childhood, Pareto lived in a middle-class environment, receiving a high standard of education, attending the newly created Istituto Tecnico Leardi where Ferdinando Pio Rosellini was his mathematics professor. In 1869, he earned a doctorate in engineering from what is now the Polytechnic University of Turin (then the Technical School for Engineers), with a dissertation entitled "The Fundamental Principles of Equilibrium in Solid Bodies". His later interest in equilibrium analysis in economics and sociology can be traced back to this dissertation. From civil engineer to classical liberal economist For some years after graduation, he worked as a civil engineer, first for the state-owned Italian Railway Company and later in private industry. He was manager of the Iron Works of San Giovanni Valdarno and later general manager of Italian Iron Works. He did not begin serious work in economics until his mid-forties. He started his career a fiery advocate of classical liberalism, besetting the most ardent British liberals with his attacks on any form