A Model To ‘Make Decisions and Take Actions’ : Leif Johansen’s Multi-Sector Growth Model, Computerized Macroeconomic Planning, and Resilient Infrastructures for Policy-Making

The 1960s were the glorious age of large-scale, “economy-wide” macroeconometric models, which enabled forecasts and simulations of the quantitative effects of certain policy changes within systems of simultaneous equations. This article is concerned (1) with the form and character of the kind of knowledge these models brought about; and (2) with the ways in which these models shaped the practices, objects, and the very notion of macroeconomic planning. The concepts of bricolage and infrastructure help to account for the continuous reciprocal shaping of mathematical techniques, empirical data, bits of economic theory, institutional arrangements, the aims and hopes of economic planning, images and visions of the economy, and the practical requirements and affordances of computing technologies. The article traces the movements and changes of the multi-sector growth model, constructed by the Norwegian economist and communist Leif Johansen, from its publication in 1960 to its implementation in national macroeconomic planning and its wider circulation under the label of “computable general equilibrium models.” In Norway, it became one component of a “system of models,” which, far from simply being a passive “tool for decision making,” structured bureaucratic procedures, and formatted the basic concepts of policy-making. Both in and outside Norway, the multi-sector growth model showed a certain resilience: when Keynesian macroeconometric models encountered widespread criticism, it was further remodeled, adapted to new scenarios, and built into easily applicable software packages. Used by international organizations, government agencies, the private sector, and academe, it provides an example for the kind of knowledge that prepares the ground for a variety of policies—regardless of their political frameworks