US federal debt-to-GDP has reached 100% of GDP, highest since WWII, with CBO forecasts consistently underestimating actual debt accumulation by 15–36 percentage points.
Macro & Markets ·
US federal debt held by the public has reached 100% of GDP, matching its highest level since World War II when the ratio peaked near 106%. This metric—which excludes intragovernmental holdings such as Social Security trust funds and measures debt owned by investors, businesses, and foreign governments—already exceeds the Congressional Budget Office's January 2017 forecast for the same period by approximately 15 percentage points.
The CBO's track record of underestimating debt accumulation extends further back. A January 2009 projection anticipated debt-to-GDP would reach roughly 42% by 2019, yet the actual ratio surged to approximately 78% in that year, overshooting the estimate by about 36 percentage points. The agency's current forecast projects the ratio will rise to approximately 120% by 2035, though analysts note that if past forecast misses persist at their typical margins, the actual figure could approach 135%.
Whether CBO projections will continue to systematically underestimate debt accumulation remains uncertain. The gap between forecast and outcome has ranged from 15 to 36 percentage points across different time horizons, leaving the true debt trajectory significantly less certain than official projections alone would suggest.