Financial fragility, sovereign default risk and the limits to commercial bank bail-outs

We analyse the poisonous interaction between bank rescues, financial fragility and sovereign debt discounts. In our model balance sheet constrained financial intermediaries finance both capital expenditure of intermediate goods producers and government deficits. The financial intermediaries face the risk of a (partial) default of the government on its debt obligations. We analyse the impact of a financial crisis, first under full government credibility and then with an endogenous sovereign debt discount. We introduce long term government debt, which gives rise to the possibility of capital losses on bank balance sheets. The negative feedback effects from falling bond prices on the economy are shown to increase with the average duration of the government bonds, as higher interest rates on new debt lead to capital losses on banks' holding of existing long term (government) debt. The associated increase in credit tightness leads to a negative amplification effect, significantly increasing output losses and declines in investment after a financial crisis. We introduce sovereign default risk through the existence of a maximum sustainable level of debt, derived from the maximum level of taxation that is politically feasible. When close to this limit, sovereign discounts emerge reflecting potential defaults on debt, creating a strong link between sovereign default risk and financial fragility emerges. A debt-financed recapitalisation of the financial intermediaries causes bond prices to drop triggering capital losses at the bank under intervention. This mechanism shows the limits to conventional bank bail-outs in countries with fragile public creditworthiness, limits that became very visible during the Great Recession in Southern Europe.