Vilfredo Pareto (vēlfrĕ´dō pärĕ´tō), 1848–1923, Italian economist and sociologist, b. Paris, of an exiled noble family that returned to Italy in 1858. He studied mathematics and engineering in Turin and worked as an engineer for many years, meanwhile becoming increasingly interested in social and economic problems. His economic writings won him (1893) a professorship of political economy at the Univ. of Lausanne. His notable contribution in applying mathematics to economic theory is found especially in Cours d'économie politique (1896–97). In his sociological studies he sought to differentiate the rational and nonrational factors in social action. He used that concept as the basis for his theory of the cyclical development and fall of governing elite groups. One of the originators of welfare economics, he defined total welfare as an improvement in a person's condition that was not achieved at any other person's expense. His chief work in sociology, Trattato di sociologia generale (1916), has been translated as Mind and Society (4 vol., 1935).
See G. C. Homans and C. P. Curtis, Jr., An Introduction to Pareto: His Sociology (1934, repr. 1970); study by F. Borkenau (1936); J. H. Meisel, ed., Pareto and Mosca (1965); R. Cirillo, The Economics of Vilfredo Pareto (1979); J. Freund, Pareto (tr. 1988).