Unfortunately, expansionary monetary policy has to create anomalies to be effective

One of the reasons why expansionary monetary policy is a "dangerous" economic policy instrument is that it has to give rise to anomalies to be effective: Interest rates that are lower than growth, which creates an abnormally high valuation of assets, eliminates market discipline for borrowers, and therefore eliminates the information and constraints normally provided by financial markets; Risk premia that are lower than those consistent with the default risk, and therefore disappearance of normal risk valuation and danger for investors in the medium term; Abnormal distortion of asset prices between those that are bought by the central bank (bonds) and those that are not (equities). These information or valuation anomalies inherent in expansionary monetary policies are in reality serious.