According to this view, deregulation, lower inflation and other factors resulted in debt expanding relative to incomes. This lifted servicing burdens relative to incomes at any given (nominal) interest rate, thereby raising the saving represented by repayments of principal. Another explanation for lower neutral rates is that they have been driven by increased inequality.
Fifthly, the conflict between roles of the regulator/supervisor and as a conductor of the monetary policy has often been discussed. This is illustrated by the case of a central bank, as a monetary authority, which may require to reduce the liquidity in the system by raising the rate of interest.