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.

The ECB has announced that when government and corporate bonds come to maturity in the context of its QE-program, new bonds will be bought in the market so as to keep the money stock (money base) unchanged. This creates a "window of opportunities" for the ECB. It could replace the old bonds with...