Tjalling Charles Koopmans, 1910-1985, was an American, Dutch born, economist and Professor at the University of Chicago, from 1946 to1955, and at Yale University, since 1955. Koopmans is mostly known for his theoretical developments in the field of econometrics, especially for works regarding optimal resources allocation. In 1975 he and Leonid Kantorovich were the joint winners of the Nobel Prize in Economic Sciences.
In his “Analysis of Production as an Efficient Combination of Activities”, 1951, Koopmans develops what is known as activity analysis, a theory that uses new ways of understanding the relations between inputs and outputs of a production process, in order to explain the correlation between efficiency in production, and the existence of a system to calculate prices. His research helped explain the links between the normative allocation theory, and the general equilibrium theory. The rigour and clarity of Koopmans works became the example to follow of mathematical economics.
His meaningful Cass-Koopmans model, which was based on Frank P. Ramsey´s previous works, is an economic growth model similar to Solow´s model, but differing in having an endogenous savings rate. This model´s aim is to establish the optimum course for investment and consumption, paying special attention to preferences and utility over time.