By answering such questions, Amartya Sen has made extensive contributions to the development and application of social choice theory. His work has been a source of inspiration to many other researchers. He has also been highly instrumental in restoring an ethical dimension to economics and related disciplines. Some of sen's studies have initiated a new and rewarding scientific approach; in other instances he has elaborated on established fielde of research. His contributions range from purely axiomatic theory of social choice, over analysis and definition of welfare indexes, to empirical studies of famine. Despite its breadth, sen's scholarly production is well integrated