This is because sovereign yields do not have to be identical in a monetary union and market discipline has an important role to play. The ECB will solely buy bonds with shorter remaining maturities. Relying on short-term debt strengthens the disciplining power of the right to stop our interventions at any point in time.
In short, OMTs strike a balance between ex ante and ex post efficiency, and they are fully compliant with the ECB mandate. Concluding remarks  Let me conclude. The euro area is still engulfed in a severe crisis, which is posing a formidable challenge to all European policy-makers.