While there are various estimates of the natural rate of interest, one way to look at it is to analyze  17  This relationship can be understood intuitively. Safe assets have the lowest rate of return. This is followed by the rate of return on the aggregate flow of goods and services in the economy.
The rate of return on all assets, including risk assets, is the highest. See also, Barro (2021). 18 I have elaborated on the other two relationships in Wakatabe (2022b). 11  developments in real interest rates.