Separation Theorems in Econometrics and Psychometrics: Rasch, Frisch, Two Fishers and Implications for Measurement

In 1959, Ragnar Frisch prompted Georg Rasch to formalise a separability theorem that continues today to serve as the basis of a wide range of theoretical and applied developments in psychological and social measurement. Previously unnoted are the influences on Rasch exerted by Frisch’s concerns for data autonomy, model identification and necessary and sufficient conditions. Although Rasch acknowledged Frisch’s prompting towards a separability theorem, he did not acknowledge any substantive, intellectual debt to him, nor to Irving Fisher, but only to Ronald Fisher. Rasch appears to have developed a special interest in sufficiency and identified models when studying with Frisch in 1935, and in 1947, when Rasch accompanied Tjalling Koopmans to the University of Chicago and the Cowles Commission for Research in Economics. I. Fisher’s separation theorem continues to be relevant in econometrics, and interest in Rasch’s separability theorem is growing as the measurement models based on it are adopted in metrological theory and practice. The extensive interrelations between measurement science, metrological standards and economics suggest paths towards lower transaction costs and more efficient markets for individualised exchanges of human, social and natural capital. Equally, if not more, surprising are the implications for a poetic art of complex, harmonised relationships played out via creative improvisations expressed using instruments tuned to shared scales. JEL: B41, C10, C13, C20, C42, D70, E60, H54, I11, I21, I31, P11

Utility Matters

The present-day standard textbook narrative on the history of growth theory usually takes Robert Solow’s 1956 contribution as a key starting point, which was extended by David Cass and Tjalling Koopmans in 1965 by introducing an intertemporal maximization problem that defines the saving ratio in the economy. However, the road connecting Solow to the Ramsey-Cass-Koopmans model is not so straightforward. We argue that in order to understand Koopmans’s contribution, we have to go to the activity analysis literature that started before Solow 1956 and never had him as a central reference. We stress the role played by Edmond Malinvaud, with whom Koopmans interacted closely, and take his travel from the French milieu of mathematical economics to the Cowles Commission in 1950-51 and back to France as a guiding line. The rise of turnpike theory in the end of the 1950s generated a debate on the choice criteria of growth programs, opposing the productive efficiency typical of these models to the utilitarian approach supported by Malinvaud and Koopmans. The Vatican Conference of 1963, where Koopmans presented a first version of his 1965 model, was embedded in this debate. We argue that Malinvaud’s (and Koopmans’s) contributions were crucial to steer the activity analysis literature toward a utilitarian analysis of growth paths.

U.S. Economics and the Quest for Scientific Authority (1932–1957)

This thesis studies the way in which economists have sought to establish the scientific authority of their discipline during the period before and after World War II in the United States. The research shows how the quest for scientific authority by economists gave rise to new concepts and notions, instruments of control, and calculation methods. Such developments contributed material and symbolic advantages to the discipline in the academic world and the broader academic sphere. By establishing itself as a type of knowledge which is at once abstract, technical and empirical, economics consolidated as a discipline capable of producing universal knowledge, of articulating the academic world and the practical sphere, and of establishing its qualifications as an applied domain for policy-making. The analysis focuses on three of the institutions at the pinnacle of the discipline in the American academic world: the Cowles Commission, the Economics department of the Massachusetts Institute of Technology, and the Economics department of the University of Chicago. By studying the standardization of the PhD program in economics, this research also studies the process of reaching a consensus within the discipline as related to the quest for the special status of 'science'. Rooted in the social history of science, this study contributes to the analysis of standards which influence today’s research, teaching, and professional activity of economists.