How large an adjustment would stabilizing the debt ratio require?
Core argument: U.S. federal debt stands at 100% of GDP, with a deficit of roughly 6.5% and a primary deficit of about 3.5%, and the measures Trump is considering would raise the primary deficit by roughly 1–2% of GDP.
The ratio of federal debt to GDP is 100%. The deficit is around 6.5% of GDP, and the primary deficit is around 3.5%. If the 2017 tax cuts were left to expire, that would shrink the deficit by roughly 1% of GDP in 2025. But even under this assumption, the Congressional Budget Office forecasts were for primary deficits of about 3% as far as the eye could see. The measures that Trump is considering would increase that number by roughly 1 to 2%, leading to a 4 to 5% sustained primary deficit and a rapid increase in the debt ratio. Were the interest rate and the growth rate to be roughly equal, which looks like a reasonable hypothesis, this would imply an adjustment of the primary deficit of 4 to 5% of GDP, or equivalently, 16 to 20% of the federal budget, to stabilize the debt ratio. It is likely, however, that a further fiscal expansion, starting from an economy close to full employment, will lead to inflation and, by implication, higher Fed policy rates and a stronger dollar.


