Why (and how) should we correct the amount of nominal interests paid by corporations for debt depreciation, so as to reach a right measure for the cost of capital?[Por qué (y como) es necesario corregir el monto de los intereses nominales pagados por las empresas por la depreciación de sus deudas, para poder lograr una evaluacion correcta del costo del capital ?]

In previous publications, we developed an indicator dedicated to measure the cost and the over-cost of financial capital, which consists in: i) the real weight of financial incomes paid by corporations compared to their effort of productive investment (cost of capital) ; ii) the share of this cost which can be attributed to a pure rent (the over-cost of capital). This indicator and the calculations conducted to arrive at it have received some criticisms. The main one is that we would have proceed in our indicator to an unjustified deflation of paid interests. So as to compute the real charge that interests make weigh on corporations, we actually applied a real interest rate to corporations' debt. This operation, according to our critics, is useless, and even amounts to the same thing as deflate twice the level of paid interests, since the denominator of our indicator is itself in current prices. In this article, we try to convince that we were right to proceed this way, and that it doesn't consist in a deflation operation. In reality, it's about the taking into consideration of the reductions linked to debt depreciation when inflation is around. As we will show, taking into account these reductions in the calculation of the cost of capital amounts to the same thing as applying a real interest rate to debts.