A safe asset is devised for the euro zone

THESE are bright days in the euro area. Preliminary figures say that the currency zone’s GDP grew by 2.5% last year, the fastest since 2007. But many of the faultlines in the zone’s financial system, as revealed by the financial crisis, remain. A proposal published on January 29th by a group reporting to the European Systemic Risk Board, a prudential supervisor, may mend one of the more troubling flaws.

Euro-area banks favour their home countries’ debt. A sample of 76 lenders examined by supervisors last year had exposures of €1.7trn ($1.9trn) to euro-area governments, of which €1.1trn was lent to their home states. That exceeded the banks’ common equity tier-1 capital, their cushion against losses, of €1trn. The fortunes of states and banks are thus bound in a “doom loop”. Suppose an economic shock raises the risk of a sovereign default. Banks’ balance-sheets start to crumble. They need propping up by the already wobbly state. And as they cut lending, the real economy weakens, worsening the fiscal woe. That, more or less, is what happened in the zone’s sovereign-debt crisis.