The Sovereign-Bank Nexus in the Euro Area: Financial & Real Channels

The sovereign-bank nexus played a key role in the 2009-12 European debt crisis by enabling pernicious dynamics whereby governments and domestic banking sectors mutually enfeebled each other. This paper reviews the direct (financial) channels and the indirect (real) channels through which banks and sovereigns interact, and that can give rise to feedback loops between the two sectors. While significant progress has been achieved in mitigating the direct channel of the loop in recent years, the indirect mechanisms of the loop stayed largely intact. Policy options for improving the financial stability of both banks and sovereigns across the euro area have been discussed, including measures to increase the diversification of banks’ sovereign debt holdings. Focusing on diversification as a standalone measure, a review of the literature and model-based simulations suggest an ambiguous impact on systemic risk. However, in those cases where diversification can either reduce total risks or keep them unchanged, it can also deliver an important shockabsorption effect in crisis periods. In such cases, simulations show that higher cross-border integration of banking sectors would dilute the impact of asymmetric shocks across the regions of a monetary union, thus increasing the overall welfare of risk averse households.