These questions, from the citation by the Swedish Academy of Sciences when Amartya Sen was awarded the Nobel Memorial Prize in Economics, refer to his work in Collective Choice and Social Welfare, the most important of all his early books. Originally published in 1970, this classic work in welfare economics has been recognized for its ground-breaking role in integrating economics and ethics, and for its influence in opening up new areas of research in social choice, including aggregative assessment. It has also had a large influence on international organizations, including the United Nations, particularly in its work on human development. In its original version, the book showed that the 'impossibility theorems' in social choice theory-led by the pioneering work of Kenneth Arrow-need not be seen as destructive of the possibility of reasoned and democratic social choice.
