Sara Lopez

Where does this fail? That proof can 'create' the equivalence between sensitivities is the weakest link in this statement. A proof only formalizes a pre-existing relationship; it is not a generative force. For example, celestial mechanics did not 'create' planetary orbits; it only allowed them to be understood. This equivalence existed before its demonstration.

Yes, proof clearly illuminates a conditionality, it's obvious! The problem is when history does not take into account hidden actors. Imagine a sudden decrease in liquidity in the bond market, an invisible player who suddenly blocks the mechanism: this much-praised equivalence collapses because the conditions for its maintenance have evaporated.

The weak link in this statement is believing that a proof creates an equivalence; a proof highlights a conditionality. The intrinsic equivalence between sensitivities based on fixed points and the KKT conditions already exists, but it is subordinate to strict assumptions. Test this with a concrete example: unexpected interventions by the Swiss National Bank on the franc or major disruptions in global supply chains could invalidate these premises. Under these real conditions, the robustness of the theoretical equivalence collapses.