"Amartya Sen has made several key contributions to the research on fundamental problems in welfare economics. His contributions range from axiomatic theory of social choice, over definitions of welfare and poverty indexes, to empirical studies of famine. They are tied closely together by a general interest in distributional issues and a particular interest in the most impoverished members of society. Sen has clarified the conditions which permit aggregation of individual values into collective decisions, and the conditions which permit rules for collective decision making that are consistent with a sphere of rights for the individual. By analyzing the available information about different individuals' welfare when collective decisions are made, he has improved the theoretical foundation for comparing different distributions of society's welfare and defined new, and more satisfactory, indexes of poverty. In empirical studies, Sen's applications of his theoretical approach have enhanced our understanding of the economic mechanisms underlying famines ...

Sen's best-known work in this area is his book from 1981: Poverty and Famines: An Essay on Entitlement and Deprivation. Here, he challenges the common view that a shortage of food is the most important (sometimes the only) explanation for famine. On the basis of a careful study of a number of such catastrophes in India, Bangladesh, and Saharan countries, from the 1940s onwards, he found other explanatory factors. He argues that several observed phenomena cannot in fact be explained by a shortage of food alone, e.g. that famines have occurred even when the supply of food was not significantly lower than during previous years (without famines), or that faminestricken areas have sometimes exported food."