When Does Higher U.S. Debt Start to Matter?

The United States has doubled its federal debt to $40 trillion in just ten years, raising critical questions about when this burden will stifle economic growth. Despite this massive public borrowing, private sector balance sheets remain remarkably resilient; U.S. corporate debt as a share of the economy is lower than pre-pandemic levels, and household debt-to-GDP has declined since 2000. This divergence suggests that higher interest rates may not trigger an immediate economic slowdown through reduced spending or borrowing. Instead, the primary risk lies in asset allocation, as 30-year Treasuries yielding 3% above inflation and corporate bonds exceeding 6% may eventually entice investors to pivot from equities to fixed income. While current fund flows do not yet show a significant shift away from stocks, the combination of rising debt and market intervention is expected to weaken the U.S. dollar, particularly against lower-debt, high-yielding currencies like the Australian dollar.