Chapter 1 focuses on the narratological strategies that turned a set of mathematical equations into an economic model in Robert Solow’s “Contribution to the Theory of Economic Growth,” the article behind the classic reference “Solow 1956.” In the first place, the paper was all about the setup of a smoothly working neoclassical growing economy, which consisted in the interplay of algebraic equations, diagrammatic visualizations, and verbal accounts. The article revolved around this artifact, made (up) by the narrator figure and, at the same time, to be used and experimented with by others, independently of its construction history. While denoting the artifact “a model” throughout, references to a world beyond its narrow boundaries were vague. Straightforward was its function as an exemplar for how proper economic reasoning should look. The text presented its model as improving a so-called precursor, the “Harrod–Domar model.” In this way, it contributed to canonizing earlier dynamic theory with its focus on instability and crisis and set the course for an angled historiography of growth theory that downplays the differences in approaches and objects until the present day.

Chapter 2 redraws the genealogies and characteristics of the different players involved in long-distance Tunisian activism. These various constellations of actors were pro-regime, Islamist, leftist and trans-ideological, and they created political parties, associations or other movements within which to conduct their politics in the trans-state space of mobilisation. This space represented a political and relational battleground on which the position of each actor played a role. The chapter shows how Tunisian activists were able to politically survive despite distance from the homeland, and the extent to which they were able to adapt to new configurations to continue their activism. The organisation of long-distance Tunisian politics assumed a specific and complex configuration in the French environment, so it cannot be considered as a simple replication of Tunisian politics.

The 1940s saw the reconciliation of mathematical wartime techniques with social scientific theorizing. This chapter examines how the economy was depicted as a huge optimization problem that would soon be solvable by electronic computers. Investigating input–output analysis as it was done at the Harvard Economic Research Project (HERP) under the directorship of Wassily Leontief illustrates the difficulties of making an economic abstraction work in measurement practice. Chapter 3 draws a trajectory to the Conference of Activity Analysis of 1949, where mathematical economists combined techniques of linear programming with what they saw as conventional economics. The move from planning tools to devices for theoretical speculation came along with a shift in modeling philosophies and notions of realism. Focusing entirely on mathematical formalisms and abandoning the concern with measurement brought about the main research object of the economics profession in the subsequent years: The economy as a flexible and efficient system of production in the form of a system of simultaneous equations. This was the economy that provided the primary point of reference for Solow’s model.

Chapter 4 situates Solow’s model in the heterogenous landscape of mathematical economics in the early 1950s. Robert Solow got acquainted with different strands of structuralist and mathematical reasoning before he devised the model more or less incidentally in the context of teaching engineering students at MIT. Here, I describe Solow’s model as a miniature not of the world but of other models. Its smaller scale and reduced mathematical form fit older mathematical economics while, at the same time, it related to the more sophisticated systems of proof and proposition characteristic of general equilibrium theory. While rigor and axiomatization also played a role in the construction of the miniature, the related style of modeling did not revolve around the austere beauty of proposition and proof. Rather, it centered on creating simple and manageable artifacts that upheld the promise of being useful tools for economic governance. The efficient shape of Solow’s model made it a particularly talkative artifact. Not least, it provided a starting point for a number of stories, including what economists themselves called “fables” or “parables” about growth.