Dear colleagues,

This is my second Hayek-related query. It appeals in particular to 
experts on the history of German-language economics. In "The Ricardo 
Effect" (1942) Hayek has the following footnote on the "internal rate 
of return":

"The term 'internal rate of return' is borrowed from Kenneth E. 
Boulding, 'The Theory of a Single Investment', Quarterly Journal of 
Economics, vol. 49, May 1935, pp. 478 et seq. Its German equivalent 
(more precisely the term 'innerer Zinssatz') has been used earlier, I 
believe, in discussions of the effects of credit rationing, but I 
cannot now recollect when or by whom."

I have been at a loss identifying the source that Hayek could not 
recollect. Therefore, I have also been unable to check if the term 
"innerer Zinssatz" is correct, or perhaps only a typing error for the 
more common "interner Zinssatz".

Once again, I will be most grateful for any help.

Hansjoerg Klausinger