L'invention des catégories énergétiques par les économistes

This chapter provides a short history of the invention of energy categories (exhaustible vs renewable) by economists. Exhaustible vs renewable are not clear categories. We can observe two semantic traditions: one starting from energy forms (coal...) to induce categories (exhaustible, renewable), the other starting from concepts (exhaustible, renewable) then applied to concrete forms (coal...). In Carnap's words (1947), we could speak about terminologies 'in extension' vs 'in intension'. Both can meet: oil helps define a category of 'exhaustible fuel' and defining ex ante such a category (non-reproducibility, thermodynamic dissipation...) allows for the inclusion of oil. Yet, in some cases, things are different. For instance, with the 'intension' method (e.g. Hotelling 1931), wood is not an exhaustible resource. But it can be considered as such with the 'extension' method (e.g. Say 1828), at times or where wood is in short supply. The advantage of the 'extension' method is that it allows a better understanding of the tensions that exist at a given time on certain energy resources. However, it makes long-term forecasting difficult, due to a strong sociotechnical contingency. The 'intension' method gives more stable categories, which is useful for historians comparing corpuses over time (e.g. to study energy transitions). Yet a drawback is that ex ante categories blur the line between natural resources and generic assets (cf. confusion on the scope of the Hotelling rule). Generally, when economists see a new subject, on the one hand they adapt their tools to the new object (acculturation), on the other hand they seek to translate this object into existing frameworks (translation). For energy, 'extension' is close to acculturation, 'intension' rather to translation. We need to find the right balance to take into account the specificities of energy resources and of sociotechnical contexts, without refusing to construct robust analytical categories. This is undoubtedly a nice challenge for the 21st century. And the history of economic thought is likely to provide here a renewed understanding of the issue.