One of the main features of post-Keynesian economics concerns the critical of the Wicksellian view of the modern theory of central banking according to which the benchmark rate of monetary policy is a natural rate of interest determined by “productivity and thrift.” From here, heterodox economists have advanced several norms on which monetary policy should be decided (Rochon and Setterfield, 2007). Among these, the one proposed by Lavoie and Seccareccia (1988,1999), the so-called Pasinetti rule, received particular attention. This rule is based on Pasinetti’s concept of the fair rate of interest. According to Pasinetti (1980-81), it should be the rate that allows debt and credit relations between individuals not to alter a distribution of national income based on the “labour principle”. However, although Pasinetti refers to a pure labor economic system, Lavoie and Seccareccia try to extend the concept of a fair interest rate to a capitalist system as well. Hence, starting from Pasinetti's original model and subsequent discussions of it (Schefold, 1982), the aim of the paper is to analyze in what cases it would be possible to apply the conclusions of this natural system to the activity of central banks in the current economic and financial system.