The Interest Rate Is a Function of the Supply and Demand for Loanable Funds

The business cycle is caused by the changes in the money supply that affect relative prices, and most importantly, the interest rate. One might consider why investors do not perceive these misleading price signals, and the reason is that individuals are not in a good position to separate out changes in prices due to changes in underlying supply and demand conditions from changes in prices due to monetary factors. In addition to the inevitable uncertainty about the future that has already been noted, as economic progress occurs, people may change their time preference. Increasing incomes can lead individuals to defer some consumption until later, saving more and consuming less in the present. This would increase the supply of loanable funds and lower the interest rate as a result of real changes in preferences rather than changes induced by monetary factors. Savers and investors can respond to market signals, but do not have a good way of separating interest rate changes caused by changes in time preference from changes due to monetary fluctuations. 

Garrison (2001) discusses changes in the interest rate that might be due to technological advances. If a new technology is developed for producing consumer goods, that technology might require investment in the short term to produce the goods that are anticipated to be profitable in the long run. An increase in investment demand will cause the interest rate to rise in the short run, but that short run might be a period of years before the technology is finally in place and able to deliver the consumer goods. This is an example with the larger point being that the interest rate is a function of the supply and demand for loanable funds. Many factors influence the supply and demand for loanable funds, and the effect of monetary expansion and contraction on the supply of loanable funds is only one factor. Entrepreneurs will, of course, try to discern and separate monetary causes for fluctuations in the interest rate from other causes, but in a complex economy nobody can do this perfectly. Market participants can see the actual market rate but can only conjecture about the importance of various factors that cause that rate to be at its current level. 

—Randall G. Holcombe, Advanced Introduction to the Austrian School of Economics, Elgar Advanced Introductions (Cheltenham, UK: Edward Elgar Publishing, 2014), 80-81.