Choice, Welfare and Measurement
by Amartya Sen
MIT Press, 460 pp., $45.00
Resources, Values and Development
by Amartya Sen
Harvard University Press, 547 pp., $29.50
Amartya Sen occupies a unique position among modern economists. He is an outstanding economic theorist, a world authority on social choice and welfare economics. He is a leading figure in development economics, carrying out path-breaking work on appraising the effectiveness of investment in poor countries and, more recently, on famine. At the same time, he takes a broad view of the subject and has done much to widen the perspective of economists. He has made major contributions to moral philosophy, being as much at home writing for the Journal of Philosophy as for the Economic Journal. He enjoys controversy, in TV debate as well as the academic seminar, and is an incisive and entertaining lecturer.
The economist seeking to take economics beyond its conventional boundaries might well find himself out of favor with his own colleagues. Not so Sen, who is a prophet with honor in his own discipline. He is Drummond Professor of Political Economy at Oxford, and was recently appointed a professor of economics and philosophy at Harvard. He has been president of the Econometric Society and of the Development Studies Association. He has recently been elected president of the International Economic Association, the previous holder of this office being Kenneth Arrow, who, together with Maurice Dobb and John Rawls, has had a major influence on Sen’s work.
On what is this formidable reputation based? The two volumes of Sen’s collected papers under review provide an opportunity to answer this question. Many people associate Sen with social choice theory and welfare economics, and these are the main topics covered in the first volume, Choice, Welfare and Measurement. Social choice theory is concerned with the relation between social judgments and the preferences of individuals. In societies such as the Western democracies in which individual preferences are the basis for social judgments, how can the different preferences be combined into a collective judgment? Kenneth Arrow’s Social Choice and Individual Values, published in 1951, contained a powerful mathematical analysis of this problem. His “impossibility theorem” showed that if one requires the procedure of reaching a collective judgment to satisfy four apparently quite reasonable conditions (such as that there are no restrictions on the way in which people rank different alternatives), then there can be no consistent social judgment.
That problems of this kind arise with majority voting had long been known, and most people will have come across the “paradox of voting,” by which in a majority vote for, say, the choice of the nation’s capital, Washington would be beaten by Boston, Boston would be beaten by Chicago, but, in a vote between Washington and Chicago, Washington would win. Arrow’s theorem shows that problems arise not just with majority voting but also with any conceivable method of aggregating individual preferences that satisfies the four conditions.
Sen has said that as an undergraduate at Cambridge University he was “besotted” with Arrow’s book. Recalling my own excitement on first reading Arrow’s work, at Cambridge some ten …