balance toward the latter. Consistent with this claim, banks with lower regulatory capital levels were also found to increase their “risky” sovereign holdings in the European sovereign crisis. Third, securities issued by sovereigns are one of the main types of collateral used by central banks in their liquidity operations with banks. As such, banks will have an incentive to hold more of these securities to be able to access the funding provided by the lender of last resort during a crisis. However, banks could take advantage of this arrangement by purchasing and pledging increasingly riskier sovereign debt as collateral in central bank operations. Using micro-level data for euro-area banks, Drechsler et al. (2013) find that both mechanisms are at play in periods of financial and sovereign stress. Banks hold more sovereign debt to be able to access liquidity from the lender of last resort, but they also shift some of their holdings to “riskier” sovereign securities. Banks’ lending activity is not the only dimension that banks can adjust in periods of sovereign stress. They can also adjust their risk-taking by arbitraging regulatory rules and the role of the lender of last resort. The main consequence of this action is an increase in systemic risk which could deepen a sovereign crisis. The question that arises from these findings is whether policy makers can adjust the system to take into account the negative structural feature embedded in the relationship between sovereigns and banks. That will be the subject of the next section. 5. Breaking the sovereign-bank “feedback loop” The close connection between banks and sovereigns leads to financial instability by amplifying any shocks that affect either sector. A country’s fiscal position typically becomes strained as it intervenes to support the banking sector during periods of financial turmoil. This in