Fractional reserve regimes generate fragile banking, and full reserve regimes (e.g., narrow banking) remove fragility at the cost of suppressing the role of banks as lenders. A Central Bank Digital Currency (CBDC) could provide safe money, but at the cost of potentially disrupting bank lending....

The paper answers three questions.(1) Does it matter if a central bank suffers a large capital loss? (2) Can the central bank become insolvent? (3) When, how and by whom should the central bank be recapitalised?