Sooner or later, the ECB must accept that monetary financing in support of deficit spending is a necessity not just for mitigating the coronavirus crisis, but also for averting a downward deflationary cycle that could pull the eurozone apart.

We reconsider the design of welfare-optimal monetary policy when financing frictions impair the supply of bank credit, and when the objectives set for monetary policy must be simple enough to be implementable and allow for effective accountability. We show that a flexible inflation targeting...