• What was predicted? Friedberg described a hypothetical mechanism: if global investors began to seriously question the U.S. government’s willingness/ability to honor its 30‑year Treasury obligations, even a small increase in perceived default risk would push 30‑year yields up by ~1–2 percentage points into the 6–7% range, raising interest costs and annual deficits in a self‑reinforcing debt spiral.

• What actually happened (through Nov 30, 2025)?

  • 30‑year U.S. Treasury yields have been elevated relative to the 2010s but have not sustained anything close to the 6–7% range. In 2023–2024, they peaked around ~5% and have more commonly traded in the 4–5% band, driven largely by inflation, Fed policy, and term‑premium dynamics rather than an outright loss of faith in repayment of U.S. debt.
  • There has been no full‑blown market episode where investors broadly priced in a serious chance that the U.S. would not meet its long‑term Treasury obligations. While ratings downgrades (e.g., S&P in 2011, Fitch in 2023) and recurring debt‑ceiling standoffs have raised concerns about governance and fiscal trajectory, markets have not treated U.S. Treasuries as if default or non‑payment over 30 years were a live probability high enough to trigger a sudden jump to 6–7% yields.
  • The U.S. is experiencing rising interest costs and larger deficits, but these have been primarily associated with higher policy rates after the post‑COVID inflation spike and ongoing primary deficits, not with a discrete, confidence‑driven default scare on 30‑year Treasuries that matches the scenario Friedberg described.

• Why the result is ambiguous rather than right/wrong:

  • This is a conditional structural claim (“if investors start to doubt repayment over 30 years, then yields jump 1–2% into the 6–7% range and a debt spiral ensues”), not a dated forecast (“by year X, 30‑year yields will be 6–7%”).
  • The key condition—global investors meaningfully doubting the U.S.’s willingness/ability to honor 30‑year Treasuries—has not clearly occurred. Without that trigger, we don’t have real‑world data to test whether yields would in fact move specifically to 6–7% and whether this would mechanically produce the spiral in the way he outlined.
  • Economic theory suggests that a sharp upward repricing of default risk would raise long‑term yields and, all else equal, worsen debt dynamics, but the exact magnitude (1–2 percentage points, to 6–7%) and the inevitability of a runaway spiral are not empirically verifiable given current history.

Because the core scenario hasn’t actually materialized, we can’t decisively say Friedberg’s quantified causal chain is either confirmed or falsified. It remains a plausible but untested mechanism, so the appropriate classification is “ambiguous.”