Results of Sensitivity Testing by Key Factor on Debt Held by the Public in GAO’s Long-Term Simulations

GAO’s sensitivity analyses show that the timing and pace of the debt build up varies depending on the assumptions used. Varying excess health care cost growth has the largest effect on growth in debt held by the public in GAO’s simulations, particularly over the long term. However, no change to a single assumption for each key factor puts federal debt on a sustainable path. This provides further support that, without policy changes, there continues to be an imbalance between revenue and spending over the long term. To see how various changes in the assumptions for each factor affect the long-term path for debt held by the public in GAO’s simulations, click on the link for each of the factors in the figure below.

Excess Cost GrowthBaselineExtendedBaselineExtended with 0.75 Percent high…BaselineExtended with 0.75 Percent lowe…AlternativeAlternative with 0.75 Percent higherexcess cost growthAlternative with 0.75 Percent lowerexcess cost growth2014201920242029203420392044204920542059050100150200Fiscal YearPercentage of GDP
YearBaseline ExtendedBaseline Extended with 0.75 Percent higher excess cost growthBaseline Extended with 0.75 Percent lower excess cost growthAlternativeAlternative with 0.75 Percent higher excess cost growthAlternative with 0.75 Percent lower excess cost growth
2014747474747474
2015747474757575
2016747474757575
2017737373767676
2018737373767676
2019747474787878
2020747474797979
2021757575818181
2022767676838383
2023777777868686
2024787878888888
2025797979919191
2026808080949494
2027828281989898
2028838483102102102
2029858685107107106
2030888987112112111
2031909290117118116
2032939592123124121
2033969895129131127
20349910297135137132
2035103106100141144138
2036106110103147151144
2037109114105154159150
2038113118108160166155
2039116122111167174161
2040120127114174181167
2041124132116181190173
2042128136119188198179
2043131141122195206185
2044135147125202215191
2045139152127209224197
2046143157130217233203
2047148163133224242209
2048152168136232251215
2049156175139240261222
2050161181142248271228
2051165187145256282235
2052170194148264293241
2053175201151273303248
2054179208153281315255
2055184215156290326261
2056189222159299338268
2057194229162308349275
2058199237165317362281
2059204245168326374288
2060210253171336387295

Source: GAO.

Note: For each factor except for excess health care cost growth, GAO gradually transitions to the sensitivity test assumption beginning in 2017. For excess health care cost growth, GAO transitions to the sensitivity test assumption after the first 10 years—in 2027. Variations for assumptions for excess health care cost growth and interest rates are generally consistent with historical variation for each of these factors. Discretionary spending and revenues are increased and decreased by 5 percent over the long term in each of the simulations.