OMTs have therefore had a self-fulfilling downward effect on yields, just as before, in absence of OMT, there was a self-fulfilling upward effect with a potentially catastrophic risk for the euro area. But this downward effect does not mean that spreads are forced to converge.
In fact, ECB intervention under OMTs would not address those parts of sovereign bond yield spreads that are fundamentally justified. The implication of a high backstop rate is that governments continue to have the incentives to raise their primary balance towards stabilising levels and to engage in structural reform.