Kenneth Joseph Arrow, born in 1921, is an American economist and Professor at Stanford University. In 1972 he was granted the Nobel Prize of Economic Sciences along with John Hicks for their pioneer contributions to general equilibrium theory and welfare economics. Arrow emerges as a great economist during post-World War II, and collaborates in the U.S. government during the 60s.
In his key work “Social Choice and Individual Values”, 1951, Arrow popularized his Impossibility theorem(firstly exposed in his Ph.D. thesis), which concludes it is not feasible to develop a social welfare function from individual welfare functions without breaking certain minimum conditions of rationality and equity. He is considered as the founder of modern economic theory of social choice and his theory has been of paramount importance in welfare economics.
Arrow, jointly with Gérard Debreu, first formally demonstrated the General Equilibrium theory, using mathematical analysis. Their work shows the existence of market clearance equilibrium if certain restrictive assumptions are met. Their work is explained in the treaty “The Existence of an Equilibrium for a Competitive Economy”, 1954.