The Fil d'Ariane: From Ancient Slavery to Contemporary Financialisation — A Note on σ_K, Marginal Cost, and the Layering of Sterile Capital

Previous notes have established three results. The blue/red partition is exhaustive and additive under declared weights (Proposition A1). Net aggregates Sc and Π are defined but not empirically identified (note "From Definition to Measurement"). σ_K, the sterile share of the capital stock, is structurally non-identified: any admissible path is absorbed by a redefined productivity term. This note extends the reflection in a different direction. It suggests that σ_K is not a static parameter but a dynamic process, produced by three mechanisms: the ageing of productive assets, the Schumpeterian shock of new technologies that lowers the marginal cost of new equipment, and the layering of financial claims on productive assets. It illustrates these mechanisms with the historical case of slavery — not because slavery is representative of contemporary economies, but because it is the simplest and most documented case in which the mechanisms appear in pure form.