Vilfredo Pareto was an Italian economist and sociologist most well knows for his theories on mass and elite interaction as well as his application of mathematics to economic analysis. Born in Paris, France, in 1848, Pareto eventually went on to graduate from the University of Turin with degrees in mathematics and physics. After college, he settled down in Florence, Italy, where he was the director of the Italian rail works in addition to being employed by a large ironworks. During his downtime, Pareto would study philosophy and politics and wrote many articles where he tried to analyze economic problems with mathematical formulas.
Pareto's first famous work, Cours d'Economia Politica, included his famous and much criticized law of income distribution where he attempted to prove that income distribution follows a mathematical formula regardless of time and place. His second second and most famous work, Manuale d'Economia Politica, is where he laid the ideas of modern welfare economics with his concept of the Pareto Optimum. This is also where the first idea of indifference curves showed up.
Toward the end of his life, Pareto realized that there were problems that economics could not solve, and he turned to Sociology. He wrote Mind and Society, his most proud work, in which he inquired into the bases of interclass interaction. He provided an idea which would create a "circulation of the elites" which argued that because the elite are content with their status, combined with the lower classes hunger for more, the elites will eventually become the lower class and the lower class would rise to replace the elites.
Pareto finally passed away in 1923 in Geneva, Switzerland. He left behind a legacy mainly upheld by his namesake ideas, Pareto-Optimal allocation of resources and the Pareto's law of income distribution. Pareto-Optimal allocation of resources attempted to explain the point in which both partners in a exchange will naturally find a point of exchange where no participant can be better off without the other being worse off. His law of income distribution showed a linear relationship between each income level and the number of people who received more than that income.
Encyclopedia Britannica. Vilfredo Pareto. 11/2/2015. http://www.britannica.com/biography/Vilfredo-Pareto
Library of Economics and Liberty. Vilfredo Pareto. 11/2/2015.http://www.econlib.org/library/Enc/bios/Pareto.html