[MaxGhenis]

test_dead_systems_modules_are_released_while_a_test_runs depends on when Python collects garbage. It failed in #2092's merge-queue run (40698045501, Test / Python 4/6) with "no release ran while the systems were built". The same test had passed in #2092's own CI, and the merge queue removed #2092. No other failed run since 26 October has this failure. The hub checked 12 failed Code changes runs. The independent review checked 20 failed runs, with 39 readable Python-job logs; one job's log returned 404.

Why it fails

The conftest releases dead systems' variable modules once more than eight systems own modules beyond those alive at the last release. Core names each module after id(system), which is the system's address (checked: a live system's id prefixes its modules, for example 4674774160_…_in_original_frs). The test builds 11 systems and expects a release.

If a collection frees a dead system during that loop, a later system can take its address. The new system then overwrites the dead system's modules instead of adding an owner, so no release falls due. Nothing leaks: the owner count stays bounded. But assert scans fails.

Measured locally on main plus #2092, with Python 3.13, 11 builds:

Loop	Distinct system ids	Owners after each build (live = 1)	Releases
As written	10	2, 3, …, 10, then 2, 3	1
gc.collect() after each build	6	2, 3, 4, 5, 6, 7, then 7 to the end	0
Automatic collection off	11	2, 3, …, 10, then 2, 3	1

The change

The test builds its systems with automatic collection off, restoring the previous setting afterwards. The dead systems then wait for the release's own gc.collect(), so each build adds an owner. The bound assertion and the hook it tests are unchanged. This is a test-only change.

Checks

Independent review: an Opus 5.5 review approved 6a82610 with no P1 or P2 findings. It confirmed from core 3.33.12 that module names carry id(self) and are assigned straight into sys.modules. It also found a second path the fix covers: a reused address can match the conftest's _adding_system and skip that build's hook. With the unchanged test bodies and real core systems, it reproduced the old test's failure, and the fixed test passed. Its mutations failed as they should: hook removed, release threshold 8 → 9, clean-up made a no-op. GC state was restored when the constructor raised, whether collection started enabled or disabled. Its two wording points are applied: this body, and the changelog fragment, at the current head.

All runs used run_capped.py, with pytest at -n 0.

Check	Result
Fixed test, twice	passed both times
Differential, run twice each. Before each build, collect only while automatic collection is enabled, as an automatic collection would.	main's test failed both times, with "no release ran while the systems were built"; this test passed both times
Mutation: remove the release hook from add_variables_from_file	this test fails ("no release ran …")
Under gc.set_threshold(700, 1, 1)	main's test and this test both passed, so thresholds alone did not reproduce it
ruff format --check, ruff check, git diff --check	clean

What the checks show: automatic collections no longer decide whether the test passes, and it still fails if the build hook stops releasing. An explicit gc.collect() during system construction would still defeat it. policyengine-core has none. Outside tests, policyengine-uk's only calls are in utils/aggregate_impact/measure.py; the conftest's release calls it on purpose.

Reproducer: policyengine_uk/tests/test_variable_module_release.py::test_dead_systems_modules_are_released_while_a_test_runs

axiom: n/a: test infrastructure only

🤖 Generated with Claude Code

[github-actions]

Aggregate impact on certified data: pass

Base df239bcc21 against head 1064189c16, both on enhanced_frs_2024_25.h5 (policyengine-uk-data 1.58.1, sha256 056e80fd8e91), fiscal years 2025-26 to 2031-32. Each year is a full microsimulation run on each side.

Checks: 0 broken by this change, 1 failing on both sides, 0 fixed. Moves flagged for review: 0 (thresholds in report_spec.yaml; a flag does not fail the job).

Workflow run and full report

Notes

• In the years a figure from fewer than 10 records is suppressed (spending.disabled_students_allowance), every total containing it, and the decile incomes, are rebuilt from their other components, so no published total includes it. Those totals are marked †. A change is withheld where the two sides leave out different figures and can't be lined up.

Moves flagged for review

None.

Spending by benefit and service

Measure	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Disabled Students' Allowance	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed

Caseloads

Measure	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Disabled Students' Allowance	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed

Standard reform costings (change in gov_balance)

Measure	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Raise additional rate by 3pp	0	0	0	0	0	suppressed	suppressed

Standard reforms: change in each reform's target

Measure	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Raise additional rate by 3pp: change in income_tax	0	0	0	0	0	suppressed	suppressed

Household net income by decile

No household's net income changes in any year.

No change in any year: receipts by tax head; government balance, each component counted once; model totals; household income totals; population; poverty rates; people in poverty; inequality; mean household net income in each side's own deciles.

Checks failing on both base and head (1)

• VAT excluding private school fees is never negative (sign:vat): 2025-26: 76 units below zero, a weighted £-53,889,156 in total; 2026-27: 76 units below zero, a weighted £-55,420,387 in total; 2027-28: 76 units below zero, a weighted £-56,618,038 in total

Counted-once check

Each of 91 components was raised by £1 per unit in 2026-27, and every head of its totals was read household by household: its own head must rise by exactly £1, no other tax head may move, no other benefit may rise, and the model's own total must move by what its heads moved. A head that breaks a rule is measured again twice: with every other head held at its baseline value, and with every other head held at its value after the first £1 while the component rises again. It fails where either still shows the response. 0 failed; 0 were skipped.

• widowed_parents_allowance: pension_credit responds only through other heads in fewer than 10 households (other heads that moved there: carers_allowance; gov_spending; not a failure)
• widowed_parents_allowance: pension_credit responds only through other heads in fewer than 10 households (other heads that moved there: carers_allowance; household_benefits; not a failure)

Provenance

Side	Commit	Runtime	Environment hash	Partition hash	Time
base	main df239bcc21	uk 2.163.0 (files 6a573e7e11a1), core 3.33.12, py 3.13.18 aarch64	79e32045b647	1eac2ca06b91	1886.15s
head	#2716 merged into main 1064189c16	uk 2.163.0 (files 6a573e7e11a1), core 3.33.12, py 3.13.18 aarch64	79e32045b647	1eac2ca06b91	1932.43s

Dataset: hf://policyengine/policyengine-uk-data-private/enhanced_frs_2024_25.h5@2526edbbb687a3b54dbb11272e5389e4b62d2ac2, sha256 056e80fd8e9151d78f432a25cde863340baee81304c6216a37fb575ce8563784 (verified on both sides), policyengine-uk-data 1.58.1.

Receipts by tax head: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Final charge on cash interest in non-cash ISAs	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Lifetime ISA withdrawal charge	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Income tax	£298.70bn	£318.31bn	£335.60bn	£350.52bn	£365.79bn	£383.53bn	£401.03bn
National Insurance (employee and self-employed)	£52.37bn	£54.71bn	£56.48bn	£58.15bn	£60.22bn	£62.11bn	£64.44bn
National Insurance (employer)	£150.59bn	£156.99bn	£161.74bn	£166.13bn	£173.24bn	£178.59bn	£185.29bn
Employer NI change borne by capital	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Employer NI change borne by consumers	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Capital gains tax	£12.61bn	£13.05bn	£13.53bn	£14.02bn	£14.52bn	£15.05bn	£15.58bn
Student loan repayments	£7.91bn	£8.21bn	£8.43bn	£8.63bn	£8.85bn	£9.10bn	£9.42bn
VAT excluding private school fees	£249.37bn	£255.28bn	£261.81bn	£267.87bn	£274.12bn	£280.56bn	£286.81bn
Change in VAT from its baseline	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
VAT on private school fees	£1.95bn	£2.00bn	£2.05bn	£2.10bn	£2.21bn	£2.21bn	£2.31bn
Change in private school VAT from its baseline	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Fuel duties	£24.53bn	£24.64bn	£26.64bn	£26.69bn	£26.42bn	£25.76bn	£26.35bn
Alcohol duties	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Tobacco duties	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Vehicle excise duties	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Betting and gaming duties	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
TV licence fee	£4.26bn	£4.41bn	£4.42bn	£4.44bn	£4.45bn	£4.47bn	£4.48bn
Council tax	£49.21bn	£51.88bn	£54.97bn	£58.29bn	£61.55bn	£64.92bn	£68.49bn
High value council tax surcharge	£0.00bn	£0.00bn	£0.00bn	£0.48bn	£0.49bn	£0.50bn	£0.51bn
Northern Ireland domestic rates	£0.55bn	£0.58bn	£0.60bn	£0.63bn	£0.66bn	£0.69bn	£0.72bn
Business rates	£34.68bn	£38.04bn	£38.88bn	£39.76bn	£43.07bn	£43.13bn	£44.57bn
Stamp duty land tax on the household's own purchases	£6.90bn	£7.39bn	£7.81bn	£8.21bn	£8.62bn	£9.02bn	£9.42bn
Stamp duty land tax paid by companies	£4.81bn	£5.98bn	£6.73bn	£7.46bn	£8.21bn	£8.87bn	£9.16bn
Land transaction tax (Wales)	£0.07bn	£0.08bn	£0.09bn	£0.09bn	£0.10bn	£0.10bn	£0.11bn
Land and buildings transaction tax (Scotland)	£0.31bn	£0.32bn	£0.34bn	£0.35bn	£0.37bn	£0.38bn	£0.40bn
Unspecified tax change borne by capital	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Unspecified tax change borne by consumers	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Wealth tax	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Wealth tax excluding the main residence	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Land value tax	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Carbon tax	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn

Spending by benefit and service: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Lifetime ISA bonus	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
State Pension	£121.64bn	£126.07bn	£127.08bn	£128.87bn	£132.52bn	£136.31bn	£140.08bn
Pension Credit	£6.66bn	£7.04bn	£7.32bn	£7.46bn	£7.60bn	£7.77bn	£7.94bn
Winter Fuel Payment	£1.86bn	£1.86bn	£1.80bn	£1.78bn	£1.79bn	£1.79bn	£1.80bn
Pension Age Winter Heating Payment (Scotland)	£0.19bn	£0.20bn	£0.20bn	£0.21bn	£0.21bn	£0.22bn	£0.22bn
Universal Credit	£75.21bn	£80.38bn	£82.93bn	£84.23bn	£85.58bn	£86.87bn	£87.97bn
Housing Benefit	£8.55bn	£8.89bn	£9.17bn	£9.31bn	£9.58bn	£9.84bn	£10.10bn
Council Tax Reduction	£2.07bn	£2.18bn	£2.32bn	£2.46bn	£2.60bn	£2.74bn	£2.89bn
Employment and Support Allowance (income-related)	£0.79bn	£0.81bn	£0.83bn	£0.85bn	£0.86bn	£0.89bn	£0.90bn
Employment and Support Allowance (contribution-based)	£5.20bn	£5.34bn	£5.46bn	£5.59bn	£5.72bn	£5.85bn	£5.99bn
Jobseeker's Allowance (income-based)	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Jobseeker's Allowance (contribution-based)	£0.29bn	£0.30bn	£0.30bn	£0.31bn	£0.32bn	£0.32bn	£0.33bn
Income Support	£0.11bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Working Tax Credit	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Child Tax Credit	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Incapacity Benefit	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Personal Independence Payment	£26.94bn	£28.06bn	£29.13bn	£29.83bn	£30.54bn	£31.26bn	£31.96bn
Disability Living Allowance	£7.49bn	£7.80bn	£8.10bn	£8.29bn	£8.49bn	£8.69bn	£8.88bn
Attendance Allowance	£8.68bn	£9.04bn	£9.38bn	£9.61bn	£9.83bn	£10.07bn	£10.29bn
Carer's Allowance	£4.48bn	£4.67bn	£4.84bn	£4.96bn	£5.08bn	£5.19bn	£5.31bn
Carer Support Payment (Scotland)	£0.31bn	£0.32bn	£0.33bn	£0.34bn	£0.35bn	£0.36bn	£0.37bn
Carer's Allowance Supplement (Scotland)	£0.00bn	£0.04bn	£0.05bn	£0.05bn	£0.05bn	£0.05bn	£0.05bn
Severe Disablement Allowance	£0.03bn	£0.03bn	£0.03bn	£0.03bn	£0.03bn	£0.03bn	£0.03bn
Industrial Injuries Disablement Benefit	£0.50bn	£0.52bn	£0.53bn	£0.54bn	£0.55bn	£0.57bn	£0.58bn
Armed Forces Compensation Scheme	£0.61bn	£0.62bn	£0.64bn	£0.65bn	£0.67bn	£0.68bn	£0.70bn
War Widow's or Widower's Pension	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Child Benefit	£16.16bn	£16.83bn	£17.43bn	£17.85bn	£18.26bn	£18.69bn	£19.10bn
Scottish Child Payment	£0.49bn	£0.52bn	£0.54bn	£0.55bn	£0.56bn	£0.57bn	£0.56bn
Two Child Limit Payment (Scotland, counterfactual)	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Healthy Start vouchers	£0.05bn	£0.05bn	£0.05bn	£0.05bn	£0.05bn	£0.05bn	£0.05bn
Maternity Allowance	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Statutory Maternity Pay	£3.30bn	£3.39bn	£3.47bn	£3.55bn	£3.63bn	£3.72bn	£3.80bn
Statutory Paternity Pay	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Statutory Sick Pay	£1.12bn	£1.15bn	£1.18bn	£1.21bn	£1.24bn	£1.27bn	£1.29bn
Sure Start Maternity Grant	£0.01bn	£0.01bn	£0.01bn	£0.01bn	£0.01bn	£0.01bn	£0.01bn
Bereavement Support Payment	£0.67bn	£0.69bn	£0.70bn	£0.72bn	£0.73bn	£0.75bn	£0.77bn
Widowed Parent's Allowance	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Tax-Free Childcare	£0.55bn	£0.56bn	£0.57bn	£0.58bn	£0.59bn	£0.61bn	£0.59bn
Extended childcare entitlement	£2.99bn	£3.50bn	£3.60bn	£3.67bn	£3.77bn	£3.85bn	£3.94bn
Universal childcare entitlement	£2.05bn	£2.23bn	£2.28bn	£2.34bn	£2.40bn	£2.47bn	£2.52bn
Targeted childcare entitlement	£0.50bn	£0.51bn	£0.52bn	£0.53bn	£0.54bn	£0.56bn	£0.52bn
Childcare Offer for Wales	£0.26bn	£0.28bn	£0.28bn	£0.29bn	£0.30bn	£0.30bn	£0.31bn
Care to Learn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Childcare Grant	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Parents' Learning Allowance	£0.20bn	£0.20bn	£0.20bn	£0.20bn	£0.20bn	£0.20bn	£0.20bn
Adult Dependants' Grant	£0.06bn	£0.06bn	£0.04bn	£0.04bn	£0.04bn	£0.04bn	£0.04bn
Travel Grant	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Disabled Students' Allowance	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed
16 to 19 Bursary Fund	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
NHS spending	£203.83bn	£204.54bn	£205.13bn	£205.79bn	£206.49bn	£207.23bn	£207.73bn
State education spending	£0.02bn	£0.02bn	£0.02bn	£0.02bn	£0.02bn	£0.02bn	£0.02bn
Transport subsidy spending	£25.05bn	£25.13bn	£25.21bn	£25.29bn	£25.37bn	£25.46bn	£25.53bn
Cost-of-living support payment	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Energy Bills Rebate	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Energy Price Guarantee subsidy	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Basic income	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Disability basic income	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Other public spending budget change	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn

Caseloads: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Lifetime ISA bonus	0k	0k	0k	0k	0k	0k	0k
State Pension	11,261k	11,158k	10,849k	10,746k	10,783k	10,822k	10,848k
Pension Credit	1,485k	1,483k	1,480k	1,461k	1,462k	1,464k	1,460k
Winter Fuel Payment	7,842k	7,793k	7,494k	7,407k	7,432k	7,459k	7,477k
Pension Age Winter Heating Payment (Scotland)	803k	803k	803k	800k	803k	806k	808k
Universal Credit	6,334k	6,341k	6,366k	6,347k	6,345k	6,333k	6,298k
Housing Benefit	1,249k	1,247k	1,250k	1,234k	1,238k	1,240k	1,239k
Council Tax Reduction	3,175k	3,198k	3,209k	3,229k	3,244k	3,257k	3,264k
Employment and Support Allowance (income-related)	71k	71k	71k	71k	71k	72k	72k
Employment and Support Allowance (contribution-based)	719k	721k	723k	726k	728k	731k	732k
Jobseeker's Allowance (income-based)	0k	0k	0k	0k	0k	0k	0k
Jobseeker's Allowance (contribution-based)	67k	67k	67k	68k	68k	68k	68k
Income Support	25k	0k	0k	0k	0k	0k	0k
Working Tax Credit	0k	0k	0k	0k	0k	0k	0k
Child Tax Credit	0k	0k	0k	0k	0k	0k	0k
Incapacity Benefit	0k	0k	0k	0k	0k	0k	0k
Personal Independence Payment	3,566k	3,579k	3,589k	3,601k	3,613k	3,626k	3,635k
Disability Living Allowance	1,291k	1,295k	1,299k	1,303k	1,308k	1,312k	1,316k
Attendance Allowance	1,694k	1,700k	1,705k	1,711k	1,716k	1,723k	1,727k
Carer's Allowance	1,034k	1,038k	1,041k	1,044k	1,048k	1,051k	1,053k
Carer Support Payment (Scotland)	71k	71k	72k	72k	72k	72k	73k
Carer's Allowance Supplement (Scotland)	0k	71k	72k	72k	72k	72k	73k
Severe Disablement Allowance	4k	4k	4k	4k	4k	4k	4k
Industrial Injuries Disablement Benefit	137k	137k	138k	138k	139k	139k	140k
Armed Forces Compensation Scheme	93k	93k	94k	94k	94k	95k	95k
War Widow's or Widower's Pension	0k	0k	0k	0k	0k	0k	0k
Child Benefit	8,102k	8,128k	8,142k	8,165k	8,191k	8,216k	8,232k
Scottish Child Payment	350k	352k	353k	357k	354k	355k	342k
Two Child Limit Payment (Scotland, counterfactual)	0k	0k	0k	0k	0k	0k	0k
Healthy Start vouchers	199k	200k	201k	201k	202k	203k	203k
Maternity Allowance	0k	0k	0k	0k	0k	0k	0k
Statutory Maternity Pay	332k	334k	335k	336k	337k	338k	339k
Statutory Paternity Pay	0k	0k	0k	0k	0k	0k	0k
Statutory Sick Pay	181k	182k	182k	183k	183k	184k	185k
Sure Start Maternity Grant	26k	26k	26k	26k	26k	27k	27k
Bereavement Support Payment	98k	98k	98k	99k	99k	99k	100k
Widowed Parent's Allowance	0k	0k	0k	0k	0k	0k	0k
Tax-Free Childcare	1,014k	1,024k	1,024k	1,027k	1,027k	1,031k	1,013k
Extended childcare entitlement	796k	801k	806k	809k	815k	819k	820k
Universal childcare entitlement	1,071k	1,074k	1,077k	1,080k	1,086k	1,096k	1,097k
Targeted childcare entitlement	165k	156k	154k	155k	155k	156k	144k
Childcare Offer for Wales	39k	39k	39k	39k	39k	39k	39k
Care to Learn	0k	0k	0k	0k	0k	0k	0k
Childcare Grant	0k	0k	0k	0k	0k	0k	0k
Parents' Learning Allowance	98k	98k	99k	99k	99k	100k	100k
Adult Dependants' Grant	18k	18k	12k	12k	12k	13k	13k
Travel Grant	0k	0k	0k	0k	0k	0k	0k
Disabled Students' Allowance	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed
16 to 19 Bursary Fund	0k	0k	0k	0k	0k	0k	0k
Cost-of-living support payment	0k	0k	0k	0k	0k	0k	0k
Energy Bills Rebate	0k	0k	0k	0k	0k	0k	0k
Energy Price Guarantee subsidy	0k	0k	0k	0k	0k	0k	0k
Basic income	0k	0k	0k	0k	0k	0k	0k
Disability basic income	0k	0k	0k	0k	0k	0k	0k

Government balance, each component counted once: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Government receipts, each component once	£898.82bn	£941.86bn	£980.11bn	£1,013.84bn	£1,052.89bn	£1,089.01bn	£1,129.10bn
Government spending	£528.95bn †	£543.83bn †	£551.68bn †	£558.06bn †	£566.57bn †	£575.31bn †	£583.38bn †
Government balance, each receipt once	£369.87bn †	£398.03bn †	£428.43bn †	£455.77bn †	£486.32bn †	£513.70bn †	£545.72bn †
Benefits in household_benefits but not in gov_spending	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn

Model totals: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
gov_tax	£898.82bn	£941.86bn	£980.11bn	£1,013.84bn	£1,052.89bn	£1,089.01bn	£1,129.10bn
household_tax	£496.91bn	£527.60bn	£554.51bn	£577.74bn	£603.32bn	£627.65bn	£654.69bn
pre_budget_change_household_tax	£489.00bn	£519.39bn	£546.08bn	£568.63bn	£593.98bn	£618.05bn	£644.75bn
gov_spending	£528.95bn †	£543.83bn †	£551.68bn †	£558.06bn †	£566.57bn †	£575.31bn †	£583.38bn †
household_benefits	£528.95bn †	£543.83bn †	£551.68bn †	£558.06bn †	£566.57bn †	£575.31bn †	£583.38bn †
gov_balance	£369.87bn †	£398.03bn †	£428.43bn †	£455.77bn †	£486.32bn †	£513.70bn †	£545.72bn †

Household income totals: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Household market income	£1,651.49bn	£1,713.03bn	£1,764.05bn	£1,812.97bn	£1,862.19bn	£1,918.39bn	£1,985.28bn
Household net income	£1,644.42bn †	£1,688.69bn †	£1,719.55bn †	£1,750.62bn †	£1,781.68bn †	£1,821.07bn †	£1,867.39bn †
Household net income (HBAI definition)	£1,457.29bn	£1,504.48bn	£1,537.58bn	£1,569.36bn	£1,602.67bn	£1,640.49bn	£1,687.04bn

Population: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
People	69,224k	69,466k	69,668k	69,891k	70,128k	70,381k	70,550k
Benefit units	35,100k	35,223k	35,325k	35,438k	35,558k	35,686k	35,772k
Households	31,037k	31,145k	31,236k	31,336k	31,442k	31,555k	31,631k

Poverty rates: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Absolute poverty, before housing costs: everyone	16.0%	15.1%	15.4%	15.5%	15.6%	15.7%	15.7%
Absolute poverty, before housing costs: children	24.0%	21.1%	21.3%	21.3%	21.5%	21.8%	21.8%
Absolute poverty, before housing costs: working-age adults	13.8%	13.5%	13.9%	14.1%	14.1%	14.2%	14.2%
Absolute poverty, before housing costs: pensioners	13.7%	13.2%	13.1%	13.4%	13.5%	13.5%	13.5%
Absolute poverty, after housing costs: everyone	21.4%	20.8%	21.3%	21.5%	21.7%	21.9%	22.2%
Absolute poverty, after housing costs: children	33.0%	30.7%	31.1%	31.1%	31.4%	31.7%	32.3%
Absolute poverty, after housing costs: working-age adults	19.8%	19.6%	20.2%	20.5%	20.7%	20.8%	21.1%
Absolute poverty, after housing costs: pensioners	12.7%	12.4%	12.3%	12.5%	12.8%	12.9%	13.0%
Relative poverty, before housing costs: everyone	17.2%	16.4%	16.5%	16.4%	16.2%	16.3%	16.5%
Relative poverty, before housing costs: children	26.2%	23.5%	23.4%	23.1%	22.6%	22.8%	23.1%
Relative poverty, before housing costs: working-age adults	14.6%	14.4%	14.7%	14.7%	14.6%	14.7%	14.8%
Relative poverty, before housing costs: pensioners	15.0%	14.8%	14.1%	14.1%	14.0%	14.0%	14.2%
Relative poverty, after housing costs: everyone	21.6%	21.0%	21.1%	21.2%	21.3%	21.4%	21.8%
Relative poverty, after housing costs: children	33.3%	31.2%	30.8%	30.7%	31.0%	31.0%	31.5%
Relative poverty, after housing costs: working-age adults	19.9%	19.8%	20.1%	20.3%	20.4%	20.5%	20.7%
Relative poverty, after housing costs: pensioners	12.9%	12.5%	12.1%	11.9%	11.8%	11.9%	12.8%

People in poverty: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Absolute poverty, before housing costs: everyone	11,057k	10,466k	10,734k	10,860k	10,960k	11,054k	11,081k
Absolute poverty, before housing costs: children	3,580k	3,171k	3,210k	3,220k	3,261k	3,305k	3,317k
Absolute poverty, before housing costs: working-age adults	5,853k	5,746k	6,021k	6,123k	6,169k	6,209k	6,219k
Absolute poverty, before housing costs: pensioners	1,625k	1,550k	1,504k	1,517k	1,530k	1,539k	1,545k
Absolute poverty, after housing costs: everyone	14,847k	14,422k	14,808k	14,994k	15,242k	15,402k	15,638k
Absolute poverty, after housing costs: children	4,937k	4,609k	4,671k	4,685k	4,757k	4,814k	4,912k
Absolute poverty, after housing costs: working-age adults	8,406k	8,359k	8,732k	8,898k	9,024k	9,114k	9,240k
Absolute poverty, after housing costs: pensioners	1,504k	1,454k	1,404k	1,411k	1,460k	1,475k	1,486k
Relative poverty, before housing costs: everyone	11,896k	11,403k	11,468k	11,487k	11,373k	11,468k	11,652k
Relative poverty, before housing costs: children	3,918k	3,523k	3,519k	3,491k	3,419k	3,458k	3,516k
Relative poverty, before housing costs: working-age adults	6,202k	6,136k	6,338k	6,400k	6,366k	6,415k	6,515k
Relative poverty, before housing costs: pensioners	1,776k	1,744k	1,611k	1,597k	1,588k	1,595k	1,621k
Relative poverty, after housing costs: everyone	14,957k	14,597k	14,698k	14,825k	14,951k	15,042k	15,351k
Relative poverty, after housing costs: children	4,976k	4,677k	4,630k	4,634k	4,690k	4,712k	4,794k
Relative poverty, after housing costs: working-age adults	8,443k	8,455k	8,680k	8,847k	8,916k	8,977k	9,092k
Relative poverty, after housing costs: pensioners	1,537k	1,465k	1,388k	1,344k	1,346k	1,354k	1,464k

Inequality: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Gini coefficient, equivalised HBAI income before housing costs	0.3085	0.3059	0.3065	0.3071	0.3075	0.3081	0.3094

Mean household net income in each side's own deciles: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Decile 1: mean household_net_income per household	£17,781 †	£17,906 †	£17,832 †	£17,905 †	£18,142 †	£18,339 †	£18,483 †
Decile 2: mean household_net_income per household	£27,962 †	£28,917 †	£28,654 †	£28,906 †	£29,096 †	£29,646 †	£30,235 †
Decile 3: mean household_net_income per household	£34,380 †	£35,463 †	£36,065 †	£36,509 †	£36,850 †	£37,338 †	£38,043 †
Decile 4: mean household_net_income per household	£38,785 †	£40,713 †	£41,873 †	£42,413 †	£43,145 †	£43,906 †	£44,167 †
Decile 5: mean household_net_income per household	£43,788 †	£44,626 †	£45,606 †	£46,289 †	£47,328 †	£48,286 †	£49,711 †
Decile 6: mean household_net_income per household	£48,210 †	£49,525 †	£50,736 †	£51,914 †	£52,203 †	£53,174 †	£54,203 †
Decile 7: mean household_net_income per household	£56,218 †	£57,224 †	£57,764 †	£58,010 †	£59,040 †	£60,061 †	£61,765 †
Decile 8: mean household_net_income per household	£69,150 †	£70,533 †	£71,800 †	£73,075 †	£74,092 †	£75,540 †	£77,427 †
Decile 9: mean household_net_income per household	£79,490 †	£81,421 †	£82,828 †	£84,135 †	£85,539 †	£87,053 †	£89,944 †
Decile 10: mean household_net_income per household	£117,581 †	£120,296 †	£121,933 †	£124,163 †	£126,045 †	£128,342 †	£131,110 †

Standard reform costings (change in gov_balance): head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Raise basic rate by 1pp	£6.47bn	£6.76bn	£6.67bn	£6.86bn	£7.06bn	£7.35bn	£7.55bn
Raise higher rate by 1pp	£3.69bn	£3.98bn	£4.03bn	£4.29bn	£4.46bn	£4.78bn	£4.91bn
Raise personal allowance by ~800GBP/year	£-3.82bn	£-3.94bn	£-4.01bn	£-4.09bn	£-4.18bn	£-4.18bn	£-2.00bn
Raise child benefit by 25GBP/week per additional child	£-1.99bn	£-1.75bn	£-1.56bn	£-1.46bn	£-1.35bn	£-1.23bn	£-1.12bn
Reduce Universal Credit taper rate to 20%	£-20.39bn	£-20.96bn	£-21.38bn	£-21.61bn	£-21.87bn	£-22.17bn	£-22.60bn
Raise Class 1 main employee NICs rate to 10%	£11.02bn	£11.42bn	£11.77bn	£12.07bn	£12.37bn	£12.75bn	£13.07bn
Raise VAT standard rate by 2pp	£24.89bn	£25.55bn	£26.14bn	£26.75bn	£27.39bn	£28.03bn	£28.66bn
Raise additional rate by 3pp	£2.96bn	£3.21bn	£3.26bn	£3.46bn	£3.65bn	suppressed	suppressed
Raise the Universal Credit standard allowance by 10%	£-3.05bn	£-3.18bn	£-3.30bn	£-3.34bn	£-3.38bn	£-3.42bn	£-3.48bn
Raise the State Pension by 10%	£-7.79bn	£-8.02bn	£-8.01bn	£-8.12bn	£-8.43bn	£-8.54bn	£-8.87bn

Standard reforms: change in each reform's target: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Raise basic rate by 1pp: change in income_tax	£6.61bn	£6.91bn	£6.83bn	£7.03bn	£7.24bn	£7.47bn	£7.73bn
Raise higher rate by 1pp: change in income_tax	£3.69bn	£3.99bn	£4.04bn	£4.25bn	£4.47bn	£4.74bn	£4.93bn
Raise personal allowance by ~800GBP/year: change in income_tax	£-3.95bn	£-4.08bn	£-4.17bn	£-4.24bn	£-4.34bn	£-4.41bn	£-1.76bn
Raise child benefit by 25GBP/week per additional child: change in child_benefit	£2.33bn	£2.14bn	£1.95bn	£1.84bn	£1.73bn	£1.62bn	£1.50bn
Reduce Universal Credit taper rate to 20%: change in universal_credit	£20.39bn	£20.95bn	£21.37bn	£21.62bn	£21.87bn	£22.22bn	£22.61bn
Raise Class 1 main employee NICs rate to 10%: change in national_insurance	£11.28bn	£11.74bn	£12.06bn	£12.37bn	£12.69bn	£13.03bn	£13.49bn
Raise VAT standard rate by 2pp: change in vat	£24.69bn	£25.35bn	£25.94bn	£26.54bn	£27.17bn	£27.81bn	£28.43bn
Raise additional rate by 3pp: change in income_tax	£2.96bn	£3.21bn	£3.26bn	£3.46bn	£3.66bn	suppressed	suppressed
Raise the Universal Credit standard allowance by 10%: change in universal_credit	£3.05bn	£3.18bn	£3.29bn	£3.36bn	£3.43bn	£3.48bn	£3.52bn
Raise the State Pension by 10%: change in state_pension	£10.68bn	£11.18bn	£11.31bn	£11.55bn	£12.00bn	£12.44bn	£12.94bn

[MaxGhenis]

UK hub: enqueued at 979024824 after all checks passed at that head.

• Independent review: Opus 5.5 approved 6a826107d with no P1 or P2 findings; the PR body summarises it.
• Since then: 979024824 changes only the changelog fragment's wording. That was the reviewer's P3, and the other P3 was a body fix.
• Next: Make Pension Credit and pension-age HB projections safe under reforms #2092 is queued directly behind this, at its unchanged head f94f9a2cb, so its merge group includes this fix.

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