Debt Sustainability and Fiscal Space in a Heterogeneous Monetary Union: Normal Times Vs the Zero Lower Bound

In this paper we study fiscal policy effects and fiscal space for countries in a monetary union with different levels of public debt. We develop a dynamic stochastic general equilibrium (DSGE) model of a two-country monetary union, calibrated to match the characteristics of Spain and Germany, in which debt sustainability is endogenously determined a la Bi (2012) to shape the responses of the risk premium on public debt. Policy shocks change the market’s expectation about future primary surplus, producing a direct effect on the sovereign risk premium and macroeconomic responses of the economy. In normal times the costs of a government spending driven fiscal consolidation in the high-debt cou…