Pure Time Preference Theory of Interest #6

In my latest post, I claimed there is more to "originary interest" than mere time preference. While in his critique of productivity theories Böhm-Bawerk downplayed the relevance of productivity to interest, at other times he overtly acknowledged it. An example is in his evaluation of the work of John Rae. "For I consider it entirely correct to think of interest as having its ultimate roots in a difference in our estimation of present and future goods. I also consider it quite correct to say that the purely psychological reasons that Rae sets forth for this difference in evaluation are a very material factor. But I consider it equally unquestionable that these reasons cannot supply an exhaustive explanation of the phenomenon of interest as it in fact exists. ... [T]here are also technological methods of production which influence interest. I am referring to those factual experiences which reduced one group of interest theorists which we have already discussed to postulate an independent 'productivity of capital.'" (Capital and Interest, Volume 1, p. 227).