The distortions created by monetary policies mask the reality of underinvestment in OECD countries

It is normally expected that if investment is too low ( there is capital underaccumulation), the interest rate is higher than the growth rate (a level of capital that is too low leads to an abnormally high marginal productivity of capital). But today in OECD countries, we are seeing both: A low investment rate and weak capital accumulation since the subprime crisis; A very low real long-term interest rate on risk-free bonds. This is shocking : if there is too little investment, the real interest rate ought to be too high. But it makes sense, as the expansionary monetary policies have driven down interest rates on risk-free bonds while, in contrast, the return on capital is very high, which is indeed consistent with the weak investment. The expansionary monetary policies have given rise to a distortion in the form of a growing gap between the return on capital and the interest rate on risk-free bonds.