Aging populations in advanced economies are placing ever-increasing demands on government spending in the form of old-age benefits. Economies that have promised substantially more benefits than they have made provision to finance are heading into a prolonged era of fiscal stress. Unresolved...

What determines the sustainability of sovereign debt? We develop a model where myopic governments seek popularity but can nevertheless commit credibly to service external debt. They do not default when debt is low because they would lose access to debt markets and be forced to reduce spending;...

We study optimal fiscal policy in a small open economy (SOE) with sovereign and private default risk. The SOE's government uses linear taxation to fund exogenous expenditures and uses public debt to inter-temporally allocate tax distortions. We characterize a class of environments in which the...

In ranking fiscal stimulus programs, it is useful to focus on the ratio of extra aggregate demand to extra national debt that results. This note argues that (because of repayment after the end of a recession) "national lines of credit"-that is, government-issued credit cards with countercyclical...

The global economy has a chronic shortage of safe assets which lies behind many recent macroeconomic imbalances. This paper provides a simple model of the Safe Asset Mechanism (SAM), its recessionary safety traps, and its policy antidotes. Safety traps share many common features with...

We study optimal fiscal and redistributive policies in an open economy without commitment. Due to its redistributive motives, the government's incentive to default on its external debt is affected by inequality. We show that in equilibrium the economy endogenously fluctuates between two regimes....

The COVID pandemic found policymakers facing constraints on their ability to react to an exceptionally large negative shock. The current low interest rate environment limits the tools the central bank can use to stabilize the economy, while the large public debt curtails the efficacy of fiscal...

Recurrent concerns over debt sustainability in emerging and developed nations have prompted renewed debate on the role of fiscal rules. Their optimality, however, remains unclear. We provide a quantitative analysis of fiscal rules in a standard model of sovereign debt accumulation and default...

The textbook optimal policy response to an increase in government debt is simple—monetary policy should actively target inflation, and fiscal policy should smooth taxes while ensuring debt sustainability. Such policy prescriptions presuppose an ability to commit. Without that ability, the...

Dynamic rational expectations models imply that the real value of debt in the hands of the public must be equal to the expected present-value of surpluses. We impose this equilibrium condition on an identified VAR and characterize the way in which the present-value support of debt varies across...