Refuting Samuelson’s Biological Theory of Interest Rate

Samuelson's biological theory of interest rate - that population growth rate and interest rate must be the same - affects many countries, especially in shaping their population and retirement policies. This paper proves that he derives his so-called theorem by many tricks, which are, however, in vain, for the result is invalid. Having disproved Samuelson's theorem, this paper then asks a more honest banker to pay back the deposited money with interest to the original saver, gives the latter more freedom to use his/her money, and indicates a profitable way to handle population and consumption