[vahid-ahmadi]

Corrects the reform impacts dashboard planning page (docs/book/validation/reform-impacts-dashboard-plan.md), written for #806.

The page itself is already on main: it shipped in #2386 (merged 21 October 2026), and its original .added changelog entry was released in 2.143.0. This branch has merged main, dropped the released fragment and now carries only corrections to main's copy of the page.

What this PR corrects (from its changelog fragment):

Updated the reform impacts dashboard plan (docs/book/validation/reform-impacts-dashboard-plan.md) for the fixture receipts, the certified Enhanced FRS 2024-25 pin and the per-pull-request aggregate-impact costings now on main, and corrected the higher-rate fixture, the external benchmarks and the two-child limit reform.

The claim-by-claim review behind these corrections, with sources, is in the "Ready for hub review" comment on this PR.

• Changelog fragment: changelog.d/806-reform-impacts-dashboard-corrections.changed.md (changed).
• Docs and changelog only; no code changes.

🤖 Generated with Claude Code

[MaxGhenis]

UK hub (Claude build session, for Max)
Ready for hub review

Head: 551399d02b264a11b0f22adb8ef6f718d9b4699d

Read this first. The page is already on main, word for word, through #2386 (d50ee85a9, merged 2026-10-21). Its changelog line shipped in 2.143.0 (CHANGELOG.md:194).

This branch now:

• merges main (cc63d6e32);
• deletes changelog.d/806.added.md;
• corrects main's copy;
• adds changelog.d/806-reform-impacts-dashboard-corrections.changed.md.

Against main, the diff is the page and the fragment. Suggested title on landing: "Update the reform impacts dashboard plan".

The plan is still worth having. #806's ask, a stored and visible history across model and data versions, is still unbuilt, though main now has most of the pieces (receipts, aggregate_impact measure, per-PR comments).

Claims checked (main a45baf5e4)

Claim	Verdict	Source
#806 asks for tracking "across model / data versions"	narrowed: the issue says "over time and model versions"	#806 body
Excerpt expected_impact: 7.8, -18.1	outdated: 7.1 and -22.0, with a dataset: block and receipts	policyengine_uk/tests/microsimulation/reforms_config.yaml:6-25,114-118
Change in gov_balance in 2029; default tolerance £1bn; microsimulation marker	true	test_reform_impacts.py:37-40,49,57,69
conftest points at enhanced_frs_2023_24.h5@1.40.3	outdated: certified pin enhanced_frs_2024_25.h5, uk-data 1.58.1, by HF commit and SHA-256	tests/conftest.py:20-29; tests/certified_dataset.yaml:7-14
Data required in the merge queue and on main; skipped on PRs without credentials	true	pr_code_changes.yaml (require-data: merge_group), code_changes.yaml (require-data: true), test-suite.yaml
"the signal is only pass or fail"	outdated: the Aggregate impact workflow posts per-PR base-vs-head costings of the standard reforms, which include the eight fixtures	.github/workflows/aggregate-impact.yaml:1-40; utils/aggregate_impact/README.md:140-147
update_reform_impacts.py overwrites the old value	true for expected_impact; old values now survive in receipts, which a test enforces	update_reform_impacts.py:87-100,156; tests/aggregate_impact/test_aggregate_impact_dataset.py:49-57
The file says the values are regression values, not external costings	true	reforms_config.yaml:1-4
Eight reforms, in this order	true	reforms_config.yaml:22,45,68,91,114,138,161,197
"Raise higher rate by 1pp"	false: sets uk[1].rate: 0.42 against a 0.40 baseline, so +2pp	reforms_config.yaml:45-48; parameters/gov/hmrc/income_tax/rates/uk.yaml (2015-04-05: 0.4)
PA to £13,000 is +£430 in 2029; frozen to 2030-31	true	reforms_config.yaml:68-71; personal_allowance/amount.yaml
Child benefit, UC taper, NI 10%, VAT +2pp, additional rate +3pp	true	reforms_config.yaml lines above
"three of the four big revenue heads"	cut: the fourth is never named and it is unsourced; the sentence also omitted the Child Benefit fixture	—
"published OBR/RF benchmark for the same reform"; "RF No half measures-style costing"	fixed: no fixture has an OBR or RF costing; HMRC's ready reckoner covers illustrative tax-rate changes; No half measures is about the two-child limit	https://www.gov.uk/government/statistics/direct-effects-of-illustrative-tax-changes (200); docs/book/validation/child-poverty-tcl.md:1-22
v2 "Remove the two-child limit (#1724)"	fixed: the baseline already removes it from 2026-04-06, so the reform is reinstating it. #1724 is open, but its page is on main as child-poverty-tcl.md	child_count.yaml:2-5; #1724 state
"Freeze the PA for an additional year"	qualified: that is 2031-32, outside the 2029 reference year	—
Fixtures "still run on the Enhanced FRS 2023-24"	outdated: 2024-25, 1.58.1	reforms_config.yaml:16-20
validation/*.ipynb Plotly pattern	made precise: only validation.ipynb uses Plotly, and notebooks need a myst.yml entry	myst.yml:20-22; docs/book/validation/
gh-pages artefact	fixed: the docs deploy through a Pages artefact	.github/workflows/deploy.yml:46
Relative ../../../policyengine_uk/... links	changed to GitHub URLs, the convention elsewhere in the docs. They rendered as static download copies	review agent's check of the deployed page
Links to nowcasting-comparison.md and rf-nowcasting-methodology.md	true	both exist in docs/book/assumptions/

Corrections: 14.

Uncertain and out of scope

• The fixture names "Raise higher rate by 1pp" (+2pp), "Raise child benefit by 25GBP/week per additional child" (sets £25) and "by ~800GBP/year" (+£430 in 2029) are misleading in code. Renaming them touches standard_reforms.yaml and the receipts test, so that is a code PR, not this one.

Full ledger: ~/reviews/uk-hub/jobs/docs-c2/b/1732-ledger.md.