Rudolph Hilferding’s scientific contributions

... This new way of formulating the problem would undoubtedly clarify the somewhat mysterious "mechanism" that is the tendency of the rate of profit to fall. 23 Our work shows that the Marxist conception of the transformation of value into market production prices is highly coherent once the allocation of capital in each branch is considered to be part of the solution, as much as the determination of the coefficients of transformation. The idealized experiment in which fixed capital and profit are zero is useful for this demonstration: it shows that the allocation of capital cannot be an exogenous datum as it is determined by the equilibrium between the commodity production and the fulfillment of the solvent need. ...

Reference:

From Marx's fundamental equalities to the solving of the transformation problem -- Coherence of the model