Arrow's impossibility theorem was set out in his PhD thesis, Social choice and individual values. It shows the impossibility of designing rules for social decision making that obey all of a number of 'reasonable' criteria. It is often known as Arrow's paradox.
Working with Gerard Debreu[?] (who won the Nobel prize for this work in 1983), Arrow produced the first rigorous proof of the existence of a market clearing equilibrium, given certain restrictive assumptions. See general equilibrium.
... is $71,726. Males have a median income of $51,332 versus $32,188 for females. The per capita income for the town is $25,466. 7.0% of the population and 4.6% of families ...