The Austerity Threshold

We introduce a new indicator of fiscal capacity—the “austerity threshold”: the debt-to-GDP level above which the government must raise fiscal surpluses to ensure debt safety. In a model with realistic risk premia, nominal rigidities, and an intermediary sector, calibrated to the U.S., we estimate this threshold at 189%. We highlight the roles of safety premia and intermediation-driven convenience yields. The threshold varies with the source of surpluses: spending cuts reduce inflation and allow low interest rates, while tax increases distort labor supply and raise inflation. Uncertainty over the austerity regime—spending cuts or tax increases—sharply lowers fiscal capacity. The expected austerity regime affects asset prices and macro outcomes even when debt-to-GDP is well below the threshold.