Tjalling Koopmans shared the 1975 Nobel Prize with Leonid Kantorovich “for their contributions to the theory of optimum allocation of resources.” Koopmans, a native of the Netherlands, started in mathematics and physics, but in the 1930s switched to economics because it was “closer to real life.” In 1938 he succeeded Jan Tinbergen at the League of Nations in Geneva and then left in 1940 when Hitler invaded the Netherlands. In the United States, Koopmans became a statistician with the Combined Shipping Adjustment Board in Washington where he tried to solve the practical problem of how to reorganize shipping to minimize transportation costs. The problem was complex: the variables included thousands of merchant ships, millions of tons of cargo, and hundreds of ports. He solved it. The technique he developed to do so was called “activity analysis” and is now called linear programming. His first write-up of the analysis is in a 1942 memorandum. His techniques were very similar to those used by Kantorovich, whose work he discovered only much later.

Koopmans was also like Kantorovich in generalizing his approach from one sector of the economy to the economy as a whole. Koopmans showed the conditions required for economy-wide efficiency in allocating resources. He also, again like Kantorovich, used his activity analysis techniques to derive efficient criteria for allocating between the present and the future.

Koopmans was an economist with the Cowles Commission at the University of Chicago between 1944 and 1955, and then moved with the Cowles Commission to Yale University, where he became a professor of economics until he retired in 1981. Koopmans became an American citizen in 1946. He served as president of the American Economic Association in 1981.

Selected Works


1942. “Exchange Ratios Between Cargoes on Various Routes (Non-refrigerating Dry Cargoes).” Memorandum for the Combined Shipping Adustment Board. 1942. Reprinted in Koopmans, Scientific Papers. Berlin: Springer, 1970.
1947. “Optimum Utilization of the Transportation System.” Proceedings of the International Statistical Conferences 5: 136–145. Reprinted in Supplement to Econometrica 17 (July 1949): 136–146.
1957. Three Essays on the State of Economic Science. New York: McGraw-Hill.
1970. Scientific Papers of Tjalling C. Koopmans. Berlin: Springer. Contains a bibliography through September 1969.