With Pratt, he lends his name to a measure of risk aversion, but he may be best known for work published in Social Choice and Individual Values.   
This man followed up "Some Ordinalist-Utilitarian Notes on Rawls' Theory of Justice" with a work examining "Nozick's Entitlement Theory of Justice", and he reviewed Sen's Poverty and Famine in a work examining "Why People Go Hungry".  He worked with Hurwicz on local stability of competitive equilibria. With Pratt, he lends his name to a measure of risk aversion, but he may be best known for work published in Social Choice and Individual Values.   For 10 points, name this economist who showed that no voting mechanism can take into account individual preferences among three or more choices in his Impossibility Theorem.
This man followed up "Some Ordinalist-Utilitarian Notes on Rawls' Theory of Justice" with a work examining "Nozick's Entitlement Theory of Justice", and he reviewed Sen's Poverty and Famine in a work examining "Why People Go Hungry".  
Kenneth Joseph {Arrow}