"The projected path of the U.S. national debt is the major challenge facing American economic policy. Without changes in tax and spending rules, the national debt will rise from 62 percent of GDP now to more than 100 percent of GDP by the end of the decade and nearly twice that level within 25...

We use discounted cash flow analysis to measure a country's fiscal capacity. Crucially, the discount rate applied to projected cash flows includes a GDP risk premium. We apply our valuation method to the CBO's projections for the U.S. federal government's deficit between 2022 and 2051 and debt...