Suchergebnisse

We study whether a pre-existing link between bank and sovereign credit risk biased euro area banks' sovereign debt portfolio choices during 2011Q4 and 2012Q1 – a period of exceptional increases in their domestic sovereign bond holdings. We find that banks whose creditworthiness is linked to that of the respective sovereign tended to purchase higher amounts of domestic sovereign bonds relative to their main assets if the CDS spreads on domestic sovereign bonds were higher. Moreover, for elevated sovereign CDS levels, banks whose creditworthiness is ex ante more strongly positively correlated with that of the local sovereign exhibit larger purchases of domestic government bonds. These findings are consistent with 'risk shifting' behaviour, where by investing in domestic government bonds banks earn the full, high risk premium while the risk is largely borne by their creditors as it materialises in states of the world where the banks are likely to be insolvent anyway. As a result, domestic sovereign debt offers ex ante higher returns to bank shareholders than alternative ways to build up precautionary liquidity buffers or indeed to execute carry trades, such as to invest in non-domestic government bonds.

We develop a model of bank risk-taking with strategic sovereign default risk. Domestic banks invest in real projects and purchase government bonds. While an increase in bond purchases crowds out profitable investments, it improves the government's incentives to repay and therefore lowers its borrowing costs. For low levels of government debt, banks influence their default risks through purchases of bonds. But, for high debt levels, this influence is lost since bank and government default are perfectly correlated. Banks fail to account for how their bond purchases influence the government's default incentives. This leads to socially inefficient levels of bond holdings.

We identify the determinants of all German banks' sovereign debt exposures between 2005 and 2013 and test for the implications of these exposures for bank risk. Larger, more capital market affine, and less capitalised banks hold more sovereign bonds. Around 15% of all German banks never hold sovereign bonds during the sample period. The sensitivity of sovereign bond holdings by banks to eurozone membership and inflation increased significantly since the collapse of Lehman Brothers. Since the outbreak of the sovereign debt crisis, banks prefer sovereigns with lower debt ratios and lower bond yields. Finally, we find that riskiness of government bond holdings affects bank risk only since 2010.This confirms the existence of a nexus between government debt and bank risk.

In European countries recently hit by a sovereign debt crisis, the share of domestic sovereign debt held by the national banking system has sharply increased, raising issues in their economic and financial resilience, as well as in policy design. This paper examines these issues by analyzing the banking equilibrium in a model with optimizing banks and depositors. To the extent that sovereign default causes bank losses also independently of their holding of domestic government bonds, under-capitalized banks have an incentive to gamble on these bonds. The optimal reaction by depositors to insolvency risk imposes discipline, but also leaves the economy susceptible to self-fulfilling shifts in sentiments, where sovereign default also causes a banking crisis. Policy interventions face a trade-off between alleviating funding constraints and strengthening incentives to gamble. Liquidity provision to banks may eliminate the good equilibrium when not targeted. Targeted interventions have the capacity to eliminate adverse equilibria.

We identify the determinants of all German banks' sovereign debt exposures between 2005 and 2013 and test for the implications of these exposures for bank risk. Larger, more capital market affine, and less capitalised banks hold more sovereign bonds. Around 15% of all German banks never hold sovereign bonds during the sample period. The sensitivity of sovereign bond holdings by banks to eurozone membership and inflation increased significantly since the collapse of Lehman Brothers. Since the outbreak of the sovereign debt crisis, banks prefer sovereigns with lower debt ratios and lower bond yields. Finally, we find that riskiness of government bond holdings affects bank risk only since 2010.This confirms the existence of a nexus between government debt and bank risk.

I propose a dynamic general equilibrium model in which strategic interactions between banks and depositors may lead to endogenous bank fragility and slow recovery from crises. When banks' investment decisions are not contractible, depositors form expectations about bank risk-taking and demand a return on deposits according to their risk. This creates strategic complementarities and possibly multiple equilibria: in response to an increase in funding costs, banks may optimally choose to pursue risky portfolios that undermine their solvency prospects. In a bad equilibrium, high funding costs hinder the accumulation of bank net worth, leading to a persistent drop in investment and output. I bring the model to bear on the European sovereign debt crisis, in the course of which under-capitalized banks in default-risky countries experienced an increase in funding costs and raised their holdings of domestic government debt. The model is quantified using Portuguese data and accounts for macroeconomic dynamics in Portugal in 2010-2016. Policy interventions face a trade-off between alleviating banks' funding conditions and strengthening risk-taking incentives. Liquidity provision to banks may eliminate the good equilibrium when not targeted. Targeted interventions have the capacity to eliminate adverse equilibria.