Intriguing pendula: founding metaphors in the analysis of economic fluctuations

The paper is an inquiry into the definition of the early econometricprogramme, namely into the discussions which Frisch and Schumpeterheld in the early 1930s about the most suitable model for representinginnovations, change and equilibrium in economics. The argument and its framework are briefly presented in thefirst section. The 1931 correspondence between the two foundersof the Econometric Society is discussed in the second section.It provides a magnificent example of the importance of rhetoricsin economics, of the heuristic role of constitutive metaphorsin a research programme and of the difficulties in definingthe most suitable mathematical formalism for dealing with cyclesand structural change. The third section presents the conclusionof the story: the bifurcation between the resulting contributionsmade by Frisch (Propagation problems and impulse problems indynamic economics, pp. 171-205 in Koch, K. (ed.), Economic Essaysin Honour of Gustav Cassel, London, Frank Cass, 1933) and Schumpeter(Business Cycles, New York, McGraw, 1939; and the posthumousvolume, History of Economic Analysis, London, Routledge, 1954).Finally, the fourth section presents an alternative epilogue,highlighting some of the hidden implications of these verbalaccounts of pendula as the founding metaphor for business cycles. The paper is based upon as yet unpublished papers that werefound in Frisch's Collections (Oslo University Library and Frisch'sRommet at the Institute of Economics) and Schumpeter's Collection(Harvard University).