Scholars in the history of economic ideas often study academic knowledge at face value, thus ignoring how its production is shaped through mechanisms of circulation, interpretation, and politicization within the public administration. Conversely, research in political history risks developing blind spots when it underestimates the implicit assumptions or premises embedded in the knowledge that structures policymakers’ thinking. With her analysis of French macroeconomic modelling between 1950 and 1975, Loipa Muñiz Duarte attempts to strike a balance between the two perspectives. Following recent literature in the history of thought, she seeks to study the economy both »in practice« and »as practices« (35). Arguably, the topic of her study is well chosen for this approach: During the first post-war decades, macroeconomic modelling in France was almost exclusively done by civil servants for the purposes of government action. Throughout the book, therefore, she does not treat models as the technocratic output of apolitical research institutes. Rather, she develops an understanding of models as »des systèmes logico‑mathématiques qui représentent une vision spécifique du monde servant à étudier les problèmes de politique économique« (28).

The author’s ultimate goal is to understand the diversity of scientific approaches towards the economy in France during the 1970s – in particular, the competitive co-existence of the regulation school and disequilibrium theories. She traces the origins of this diversity to the models developed within the public administration from 1950 through 1975, asking in how far this period proved decisive for the evolution of modelling in a peculiar French way (29–31). The main actors in the analysis, therefore, are scholars that worked in the Ministry of Finance’s research departments: The Service des études économiques et financières (SEEF, until 1965) and the Direction de la Prévision (DP, after 1965). Her analysis is based on published research, primary sources from within the Ministry of Finance, and twelve interviews with former researchers.

In the first chapter, the author studies the nexus between national accounting and macroeconomic modelling at the SEEF from 1950 to 1965. Models were static at first but helped in developing the annual economic budget. These budgets were not only an accounting practice, but »un exercice de prévision où il est nécessaire de prendre en compte les comportements des agents et les hypothèses de conjoncture« (112). The SEEF diversified the initial approach during the 1950s. In face of growing forecasting uncertainties, its researchers created exploratory and provisional budgets based on different variants of economic hypotheses. After 1958, institutional restructuring and the creation of the European common market induced a new generation of economists to abandon the static approaches in favour of econometric models.

The second chapter is dedicated to the institutionalisation of modelling at the DP from 1965 to 1970. The DP was created by Valéry Giscard d’Estaing as Minister of Finance to develop an intellectual counterweight to the Planning Commission. However, while consolidating its position within the Ministry, the DP collaborated closely with other public entities such as the Plan and the statistical institute INSEE. Its Division des budgets économiques elaborated a diversified toolbox for the rationalisation of public intervention. The econometric research resulted in the 1966 ZOGOL and the 1968 DECA models. DECA in particular was designed to integrate short-term forecasts with multi-annual planning. Its defining features included the analysis of corporate self-financing, investment cycles, and the endogenization of wages. As a dynamic, iterative framework, it represented an important academic innovation, enabling a coherent assessment of how different economic policy decisions affected the economic budget – an approach called »Opération OPTIMIX«.

The third and last chapter shows that the integration of short- and long-term forecasts became an ever more pressing issue during the early 1970s. In the eyes of the Ministry, DECA did not yet show sufficient results to solve this problem, so the DP‑scholars at the new Groupe de recherches macroéconomiques (GRM) launched another try. This effort resulted in the 1974 STAR model. Importantly, STAR used a different notion of investment based on the so-called Cambridge school. Here, investment was not determined by corporate expectations of profits, but the partition of national income between capital and labour and the path of prior capital accumulation – bringing it closer to the original concept in national accounting. Per consequence, STAR had no production function, and price levels were determined only implicitly. In doing so, it departed from the international consensus in economics.

The STAR approach was strongly criticised by other parts of the public administration, and the model was never truly applied to policy purposes. However, with the first oil shock in late 1973, the end of the Bretton-Woods system of fixed exchange rates, and accelerating structural economic change, many of STAR’s perceived shortcomings became an asset. From there, it laid the foundation for the French regulation school. Meanwhile, other researchers followed the makeover of disequilibrium models in the international community. This evolution ultimately produced the diversity of approaches that were the study’s original interest.

Overall, the analysis is a well-researched reconstruction of modelling practices in France, based on thorough source analysis. The oral history is a particularly fruitful contribution. Without neglecting the technical details of the various models, the author is sensible for the political, economic and institutional circumstances that shaped model building. She underlines French peculiarities as well as outside influences. Furthermore, the integration of short‑term forecasts with long-term planning practices is a recurring feature worth studying in closer detail. In so far, the book is a very welcome contribution to the history of economic thought in the French of post-war context.

The author concludes that the models were not ultimately intended to produce highly specific economic forecasts, a task assigned to other tools. Rather, they offered »un cadre théorique cohérent servant de langage commun aux responsables des prévisions« (282). While this is a valuable insight, the analysis could have gone further. The book is most compelling when it links the details of modelling to specific policy implications. Unfortunately, these connections remain under-developed. The author’s ex‑post focus on explaining the 1970’s models leads to analytical dead ends where the contingent and practical implications of the current models would have been particularly illuminating. Correspondingly, the study remains closely aligned with a relatively narrow body of scholarship in the history of economic thought and engages only marginally with other strands of economic or political history.