Remove the cap on the state and local tax deduction, scored against current law — P.L. 119-21 sec. 70120 sets it at $40,400 in 2026 rising 1%/yr through 2029, phased down above $500K of income, reverting to $10K in 2030. Penn Wharton's ~$1.17T prices the same repeal against a permanent $10K cap, and ~$197B against a baseline where the cap expires.
Ten-year deficit effect, conventional+$740.3Badds to the deficit
With macroeconomic feedback and debt service+$831.8BFRB/US-Lite (Federal Reserve calibrated)
Checked against
Published score +$1,169.0B; this estimate is 1.1% away (unfitted reconstruction). Unfitted reconstruction, 1.1% from $1.17T (Penn Wharton Budget Model) — no constant is fitted to this figure.
Typical error for this kind of policy: +$687.7B to +$792.9B, from 2 out-of-sample tax expenditure cases.
Out-of-sample accuracy, tax expenditure: 2 pre-registered rows miss their published scores by 7.1% on average (median 7.1%), worst 12.8% — 1 of the 2 falls inside the average. On this figure that is +$687.7B to +$792.9B typical, +$645.5B to +$835.1B 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.
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.
Economic effects
difference from the CBO baseline
GDP, summed over the window+0.77percent-years
Jobs at the largest effect+95K
Deficit effect of the GDP change-$53.7Bmore tax collected
Deficit effect of interest on the debt+$145.2Bmore debt, more interest
Fiscal year
GDP level
Jobs
Unemployment
10-year rate
GDP change, deficit
Interest, deficit
2026
+0.129%
+83K
-0.06 pt
+0.01 pt
-$9.0B
+$2.1B
2027
+0.149%
+95K
-0.07 pt
+0.01 pt
-$10.4B
+$4.3B
2028
+0.130%
+83K
-0.07 pt
+0.02 pt
-$9.1B
+$6.5B
2029
+0.102%
+65K
-0.05 pt
+0.02 pt
-$7.1B
+$8.8B
2030
+0.082%
+53K
-0.04 pt
+0.03 pt
-$5.8B
+$12.0B
2031
+0.062%
+40K
-0.03 pt
+0.04 pt
-$4.3B
+$15.3B
2032
+0.045%
+29K
-0.02 pt
+0.05 pt
-$3.1B
+$18.6B
2033
+0.031%
+20K
-0.02 pt
+0.06 pt
-$2.2B
+$22.2B
2034
+0.022%
+14K
-0.01 pt
+0.07 pt
-$1.5B
+$25.8B
2035
+0.015%
+9K
-0.01 pt
+0.08 pt
-$1.0B
+$29.6B
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: +$740.3B - $53.7B + $145.2B = +$831.8B.
Other scoring models
exploratory
Model
Ten-year deficit effect
Method
CBO-Style
+$740.3B
Static + ETI behavioral response + optional FRB/US dynamic feedback
TPC-Microsim Pilot
Cannot score this
SALT cap reforms need itemized-deduction / state-and-local-tax columns that the pilot microdata does not carry.
No pilot model returned distributional output; the comparison is aggregate-only.
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.
Limitations
holdout labels follow the locked post-2026-05-02 regression protocol; they are not retroactive historical out-of-sample claims.
Target revised (target_revisions.eliminate_mortgage.v2) to a published RANGE [-$495.0B, -$367.9B] with Tax Foundation's -$367.9B as the carried anchor. The percentage this row reports is a distance from one modeller's point, not a measurement of accuracy; read `within_published_range` and `distance_to_published_range_billions` instead. No agency has scored repeal: CBO has published no post-TCJA option, JCT publishes the tax expenditure, and there is no FY2027 Green Book.
Yale's own 'close to $1.2 trillion' is not a bound: it is scored against pre-P.L. 119-21 current law, where TCJA's larger standard deduction lapses and the itemising population roughly doubles.
The record's annual_cost = 25.0 is a pre-P.L.119-21 level. JCT's JCX-45-25 puts the capped expenditure at $45.5B in FY2025 rising to $54.9B in FY2029, because raising the SALT cap to $40,000 took itemising claimants from 11.8M to 17.8M returns; Treasury's FY2027 edition gives $23.9B falling to $14.1B on the same statute. Choosing between them is an owner decision with a visible consequence for this row, not a provenance lane's.
The target and this benchmark's twin `eliminate_salt` state opposite baselines: repeal is priced against a permanent $10,000 cap and elimination against CBO's world where the cap has lapsed. Both are now stated rather than hidden; reconciling them needs a baseline-vintage concept the expenditure module does not have.
P.L. 119-21 sec. 70120 replaced the $10,000 cap with $40,000 for 2025-2029 (indexed 1%/yr, phased down above $500,000 of MAGI, never below $10,000) reverting permanently to $10,000 in 2030, so 'repeal the $10,000 cap' describes no live reform for most of the window. JCT's own row for that provision is +$946.2B over FY2025-2034 and is already carried as `pl119_21_salt_cap_40k`.
CBO measures the option on a baseline where the $10,000 cap lapses after 2025. P.L. 119-21 has since replaced that world with a $40,000 cap through 2029 reverting to $10,000 in 2030, so the target's baseline is no longer current law -- a model gap, not a target one, and one that needs a baseline-vintage concept the module does not have.
Reclassified rather than retuned: the module's behavioural magnitude for a charitable benefit-rate ceiling was an unsourced 0.40, and this annual had been chosen so that static x 1.40 lands on -$200.0B. Lane H7 derived the magnitude from CRS R40518's central price elasticity of giving (0.5) through the deduction's own SOI distribution, giving 0.220780, and the row moved 0.3% -> 12.5%; no constant was moved to close it.
The -$200B target is itself `secondhand` and sits in EXAMINED_NOT_REVISED: the 28% limitation it points at is a real Green Book proposal with a real score, but that proposal limits the value of ALL itemized deductions plus several exclusions, so its $645,538M is not a charitable-only cap. The residual is therefore a distance from an unsourced figure rather than a measurement against a document.
Cite asWilse-Samson, Laurence. “Repeal SALT Cap.” Fiscal Policy Calculator, CBO February 2026 baseline, FY2026-2035. https://fiscal.lwilsesamson.com/explore/salt-cap-repeal