We revisit the optimal-contract approach to the design of monetary institutions, in the light of the Zero Lower Bound (ZLB) on interest rates and the resort to Quantitative Easing (QE) in recent years. Four of our lessons have not yet been incorporated in the practices of inflation targeting...

This paper shows the existence of a central bank trilemma. When a central bank is involved in financial intermediation, either directly through a central bank digital currency (CBDC) or indirectly through other policy instruments, it can only achieve at most two of three objectives: a socially...