Two Classics: Böhm-Bawerk's Positive Theory and Fisher's Rate of Interest Through Modern Prisms

Positive Theory of Capital (1889) is a classic which contains Eugen von Böhm-Bawerk's 1889 correct vision of how the interest rate might be determined by the interplay of systematic time preference (“impatience†) and time-phased technology's productivity. But he was not quite able to formulate his intuitive vision in terms that would satisfy today's persnickety jury of theorists. And indeed the classic Rate of Interest (1907) by his younger contemporary, Irving Fisher, seemed to be disagreeing with Böhm-Bawerk's treatment of time's net productivity; but, as Fisher was unable to make clear until 1930, he was objecting only to Böhm-Bawerk's formulation of the role of productivity in interest determination. In point of fact, Fisher, who was so long identified (wrongly, but understandably) as an “impatience theorist,†considered his own main contribution to interest theory to be his clarification of how the technological superiority of time-consuming processes cooperated in the determination of the equilibrium interest rate.