An Interview with Paul A. Samuelson

It is customary for the Interviewer to begin with an introduction describing the circumstances of the interview and providing an overview of the nature and importance of the work of the interviewee. However, in this case, as Editor of this journal, I feel it would be presumptuous of me to provide my own overview and evaluation of the work of this great man, Paul Samuelson. The scope of his contributions has been so vast (averaging almost one technical paper per month for over 50 years) that it could be particularly difficult to identify those areas of modern economic theory to which he has not made seminal contributions.1 In addition to his over 550 published papers, his books are legendary. He once said: "Let those who will?write the nation's laws?if I can write its textbooks." Instead of attempting to provide my own overview, I am limiting this introduction to the following direct (slightly edited) quotation of a few paragraphs from the Web site, The History of Economic Thought, which is maintained online by the New School University in New York: Perhaps more than anyone else, Paul A. Samuelson has personified mainstream economics in the second half of the twentieth century. The writer of the most successful principles textbook ever (1948), Paul Samuelson has been not unjustly considered the incarnation of the economics "establishment"?and as a result, has been both lauded and vilified for virtually everything right and wrong about it. Samuelson's most famous piece of work, Foundations of Economic Analysis (1947), is one of the grandest tomes that helped revive Neoclassical economics and launched the era of the mathematization of economics. Samuelson was one of the progenitors of the Paretian revival in microeconomics and the Neo-Keynesian Synthesis in macroeconomics during the post-war period. The wunderkind of the Harvard generation of 1930s,where he studied under Schumpeter and Leontief, Samuelson had a prodigious grasp of economic theory, which has since become legendary. An unconfirmed anecdote has it that at the end of Samuelson's dissertation defense, Schumpeter turned to Leontief and asked, "Well, Wassily, have we passed?" Paul Samuelson moved on to M.I.T. where he built one of the century's most powerful economics departments around himself. He was soon joined by R.M. Solow, who was to become Samuelson¡¯s sometime co-writer and partner-in-crime. Samuelson's specific contributions to economics have been far too many to be listed here? being among the most prolific writers in economics. Samuelson's signature method of economic theory, illustrated in his Foundations (1947), seems to follow two rules which can also be said to characterize much of Neoclassical economics since then: With every economic problem, (1) reduce the number of variables and keep only a minimum set of simple economic relations; and (2) if possible, rewrite it as a constrained optimization problem. In microeconomics, he is responsible for the theory of revealed preference (1938, 1947). This and his related efforts on the question of utility measurement and integrability (1937, 1950) opened the way for future developments by Debreu, Georgescu-Roegen, and Uzawa. He also introduced the use of comparative statics and dynamics through his ¡°correspondence principle¡± (1947), which was applied fruitfully in his contributions to the dynamic stability of general equilibrium (1941, 1944). He also developed what are now called ¡°Bergson-Samuelson social welfare functions¡± (1947, 1950, 1956); and, no less famously, Samuelson is responsible for the harnessing of ¡°public goods¡± into Neoclassical theory (1954, 1955, 1958). Samuelson was also instrumental in establishing the modern theory of production. His Foundations (1947) are responsible for the envelope theorem and the full characterization of the cost function. He made important contributions to the theory of technical progress (1972). His work on the theory of capital is well known, if contentious. He demonstrated one of the first remarkable ¡°Non-Substitution¡± theorems (1951) and, in his famous paper with Solow (1953), initiated the analysis of dynamic Leontief systems. This work was reiterated in his famous 1958 volume on linear programming with Robert Dorfman and Robert Solow, wherein we also find a clear introduction to the ¡°turnpike¡± conjecture of linear von Neumann systems. Samuelson was also Joan Robinson¡¯s main adversary in the Cambridge Capital Controversy?introducing the ¡°surrogate¡± production function (1962), and then subsequently (and graciously) relenting (1966). In international trade theory, he is responsible for the Stolper?Samuelson Theorem and, independently of Lerner, the Factor Price Equalization theorem (1948, 1949, 1953), as well as (finally) resolving the age-old ¡°transfer problem¡± relating terms of trade and capital flows, as well as the Marxian transformation problem (1971), and other issues in Classical economics (1957, 1978). In macroeconomics, Samuelson¡¯s multiplier-accelerator macrodynamic model (1939) is justly famous, as is the Solow?Samuelson presentation of the Phillips Curve (1960) to the world. He is also famous for popularizing, along with Allais, the ¡°overlapping generations¡± model which has since found many applications in macroeconomics and monetary theory. In many ways, his work on speculative prices (1965) effectively anticipates the efficient markets hypothesis in finance theory. His work on diversification (1967) and the ¡°lifetime portfolio¡± (1969) is also well known. Paul Samuelson¡¯s many contributions to Neoclassical economic theory were recognized with a Nobel Memorial prize in 1970.