How should public debt be managed when uncertainty about the business cycle is widespread and debt levels are high, as in the aftermath of the last financial crisis? This paper analyzes optimal fiscal policy with ambiguity aversion and endogenous government spending. We show that, without...

The question of what is a sustainable public debt is paramount in the macroeconomic analysis of fiscal policy. This question is usually formulated as asking whether the outstanding public debt and its projected path are consistent with those of the government's revenues and expenditures (ie,...