Something is needed that can hold the euro-zone countries together
The euro zone’s spontaneous trend is growing heterogeneity, which may lead to its break-up. The zero or negative interest rates implemented by the ECB ha ve given the member countries fiscal space , enabl ing them to combat this heterogeneity. But this is not a normal and sustainable remedy against heterogeneity, which is: First, capital mobility between the member countries, which makes it possible to harmonise per capita capital and per capita GDP; Second, a federal budget financed by common public debt (eurobonds).