This paper evaluates the macroeconomic effects of purchases of long-term sovereign bonds by a central bank in a monetary union when (1) the private sector faces tight financial conditions and (2) the zero lower bound (ZLB) on the policy rate holds. To this end, we calibrate a dynamic general equilibrium model to the euro area (EA).
We assume that households in one member country have a large initial debt position and are subject to a borrowing constraint. We simulate the effects of a negative EA-wide demand shock that induces a decline in inflation. The main results are as follows. First, the reduction in inflation amplifies the domestic and cross-country spillovers of the negative demand shock because of the country-specific borrowing constraint and the ZLB. Second, sovereign bond purchases boost economic activity and, hence, indirectly allow households to reduce their debt and relax the borrowing constraint. Third, the new, lower value of debt allows households to smooth consumption, fostering macroeconomic resilience not only in the member country concerned but also in the rest of the monetary union.