2.6pp on income above $400K, restoring the pre-TCJA 39.6% top rate. Treasury FY2025 Green Book estimate: raises ~$252B over 10 years.
Published score -$245.9B; this estimate is 21.9% away (out-of-sample prediction). Out-of-sample prediction, 21.9% from -$246B (U.S. Treasury) — pre-registered before it was scored.
Typical error for this kind of policy: -$348.5B to -$256.0B, from 11 out-of-sample ordinary rate change cases.
Out-of-sample accuracy, ordinary rate change: 11 pre-registered rows miss their published scores by 15.3% on average (median 15.0%), worst 40.6% — 6 of the 11 fall inside the average. On this figure that is -$348.5B to -$256.0B typical, -$424.9B to -$179.5B at the worst row. Read off the out-of-sample tier only — not the calibrated tiers, whose agreement is by construction. It is the observed spread of this model against published scores for this class of policy, not a confidence interval.
| Fiscal year | Revenue | Deficit, conventional | Macro feedback | Debt service | Deficit, dynamic |
|---|---|---|---|---|---|
| 2026 | +$28.8B | -$25.2B | -$4.4B | -$1.0B | -$21.8B |
| 2027 | +$30.1B | -$26.3B | -$5.2B | -$2.1B | -$23.2B |
| 2028 | +$31.3B | -$27.4B | -$4.6B | -$3.2B | -$26.0B |
| 2029 | +$32.5B | -$28.4B | -$3.6B | -$4.3B | -$29.1B |
| 2030 | +$33.8B | -$29.5B | -$2.7B | -$5.5B | -$32.3B |
| 2031 | +$35.0B | -$30.7B | -$2.0B | -$6.7B | -$35.4B |
| 2032 | +$36.4B | -$31.8B | -$1.4B | -$8.0B | -$38.4B |
| 2033 | +$37.7B | -$33.0B | -$1.0B | -$9.3B | -$41.3B |
| 2034 | +$39.2B | -$34.3B | -$0.7B | -$10.7B | -$44.3B |
| 2035 | +$40.6B | -$35.6B | -$0.5B | -$12.1B | -$47.2B |
| Income group | Returns | Average change | Share of income | Share of total | Paying more | Paying less | Tax rate before | Tax rate after |
|---|---|---|---|---|---|---|---|---|
| Lowest Quintile | 56.4M | $0 | 0.00% | 0.0% | 0.0% | 0.0% | -3.5% | -3.5% |
| Second Quintile | 37.8M | $0 | 0.00% | 0.0% | 0.0% | 0.0% | 3.5% | 3.5% |
| Middle Quintile | 28.4M | $0 | 0.00% | 0.0% | 0.0% | 0.0% | 7.4% | 7.4% |
| Fourth Quintile | 19.5M | $0 | 0.00% | 0.0% | 0.0% | 0.0% | 9.9% | 9.9% |
| Top Quintile | 18.3M | +$1,709 | 0.51% | 100.0% | 15.0% | 0.0% | 20.3% | 20.7% |
Return-level microsimulation on CPS ASEC tax units calibrated to IRS data: the validated distributional tier. Groups are ranked by adjusted gross income per return. Average change is in dollars per return; positive means the group pays more tax.
| Fiscal year | GDP level | Jobs | Unemployment | 10-year rate | GDP change, deficit | Interest, deficit |
|---|---|---|---|---|---|---|
| 2026 | -0.063% | -40K | +0.03 pt | -0.00 pt | +$4.4B | -$1.0B |
| 2027 | -0.074% | -47K | +0.04 pt | -0.01 pt | +$5.2B | -$2.1B |
| 2028 | -0.066% | -42K | +0.03 pt | -0.01 pt | +$4.6B | -$3.2B |
| 2029 | -0.052% | -33K | +0.03 pt | -0.01 pt | +$3.6B | -$4.3B |
| 2030 | -0.039% | -25K | +0.02 pt | -0.01 pt | +$2.7B | -$5.5B |
| 2031 | -0.028% | -18K | +0.01 pt | -0.02 pt | +$2.0B | -$6.7B |
| 2032 | -0.020% | -13K | +0.01 pt | -0.02 pt | +$1.4B | -$8.0B |
| 2033 | -0.014% | -9K | +0.01 pt | -0.02 pt | +$1.0B | -$9.3B |
| 2034 | -0.010% | -6K | +0.00 pt | -0.03 pt | +$0.7B | -$10.7B |
| 2035 | -0.007% | -4K | +0.00 pt | -0.03 pt | +$0.5B | -$12.1B |
FRB/US-Lite (Federal Reserve calibrated). Demand effects fade over five to seven years as monetary policy responds; there is no supply-side channel. The dynamic score is the conventional score, plus the deficit effects of the GDP change and of interest on the debt: -$302.2B + $26.0B - $62.7B = -$338.9B.
| Model | Ten-year deficit effect | Method |
|---|---|---|
| CBO-Style | -$302.2B | Static + ETI behavioral response + optional FRB/US dynamic feedback |
| TPC-Microsim Pilot | -$355.6B | Single-year CPS-style microsimulation with flat-horizon annualization and quintile distribution output. Default microdata is already SOI-calibrated (top tail included); no separate top-tail augmentation applied. Maps to microsim reforms: income_rate_change, income_rate_change_threshold. Income-tax rate changes are applied to ordinary taxable income above the policy threshold ($400,000) in the pilot microsim. |
CBO-Style is the model behind the headline above. The TPC-style microsimulation is a pilot: where the two disagree, the gap tells you how much the answer depends on method. It is not an official range.
Cite asWilse-Samson, Laurence. “Biden 2025 Proposal.” Fiscal Policy Calculator, CBO February 2026 baseline, FY2026-2035. https://fiscal.lwilsesamson.com/explore/top-rate-39-6