Rather than issuing "perpetual bonds" whose value can fluctuate widely in the secondary market, I suggest that the EU budget be authorized to issue (to start) up to € 1 trillion to finance the recovery. The bonds of various maturities would have one common novel feature: they would be accepted by all Member States in payement of any fiscal claim and could in turn be used by the Member State to meet the cash calls made by the EU budget.

This feature would ensure that the bonds (always carrying a zero% coupon) would always trade close to par (like the US 3months treasury bills), being issued at a slight discount or premium depending on market conditions. It would create also a deep liquid "safe asset" market underpinning the stability of the € and could be used by the ECB to regulate the € money market.

(see more complete description on my web site: www.paulgoldschmidt.eu