Optimal monetary–fiscal policy in the euro area liquidity crisis

We build an euro-area level DSGE model featuring a liquidity shock in the sovereign bonds market to simulate the strong contraction in economic activity observed during the 2008–2009 crisis. In the model, a sudden deterioration of the liquidity property of sovereign bonds is associated with deep recession and deflation. Against this background we characterize optimal monetary and fiscal policy with full commitment. We find that the optimal policy contains three features: (i) the policy rate is lowered until hitting the zero lower bound (ZLB) and then is kept at the ZLB for more periods; (ii) a prolonged central bank’s balance-sheet expansion aimed at restoring the liquidity deteriorated; (iii) a counter-cyclical fiscal stimulus which offsets, to a large extent, the fall in private spending caused by the liquidity shock. Policy regimes involving (i), but not (ii) and (iii), are quite weak in stabilizing output gap and inflation. Monetary policy regimes such as full inflation-targeting or nominal GDP targeting perform remarkably well insofar as they are complemented with an optimally-implemented counter-cyclical fiscal policy. Our results tend to favour the view that, in case of recession, an euro-wide coordinated fiscal policy should supplement the role of the ECB in achieving its primary objective.