[MaxGhenis]

Fixes #2755

What and why

create_economic_assumption_indices built every cumulative index with range(start_year + 1, 2040), while the growth series run to 2074. A Parameter carries its last value forward rather than raising, so everything grown by an index froze at its 2039 level with no error. That covers the State Pension, the tax thresholds, benefit rates, and the inputs Core grows by variable.uprating after PROJECTION_END_YEAR.

The indices now end at growth_horizon(yoy_growth), the last year any growth series covers. They end in 2074, one year past yoy_growth.yaml, because the lagged series run a year past their source. The indices read each series on 1 January, so a value dated later in a year counts from the year after. Fiscal-year conversion needs no change: af5d07a made it follow each parameter's stated dates.

State Pension path and totals, 2035 to 2050

I ran main (37591f4) and this branch on the certified dataset, enhanced_frs_2024_25.h5 at 2526edbb, in full Microsimulation runs. Weekly rates in pounds; totals in £bn, by model year.

Year	New SP, main	New SP, fix	Basic SP, main	Basic SP, fix	SP total, main	SP total, fix	gov_tax, main	gov_tax, fix	gov_spending, main	gov_spending, fix
2035	313.90	313.90	240.53	240.53	159.2	159.2	1,289	1,289	617.8	617.8
2036	325.20	325.20	249.19	249.19	165.1	165.1	1,338	1,338	627.1	627.1
2037	337.56	337.56	258.66	258.66	171.6	171.6	1,391	1,391	636.5	636.5
2038	350.38	350.38	268.49	268.49	178.2	178.2	1,444	1,444	646.3	646.3
2039	363.70	363.70	278.69	278.69	185.2	185.2	1,500	1,500	656.5	656.5
2040	363.70	377.52	278.69	289.28	185.2	192.4	1,501	1,558	656.5	666.5
2041	363.70	391.86	278.69	300.27	185.2	199.8	1,501	1,618	656.5	675.8
2042	363.70	406.75	278.69	311.68	185.2	207.6	1,501	1,681	656.5	686.0
2043	363.70	422.21	278.69	323.53	185.2	215.6	1,501	1,747	656.5	697.2
2044	363.70	438.26	278.69	335.82	183.7	222.1	1,501	1,815	655.0	707.0
2045	363.70	454.91	278.69	348.58	180.2	226.3	1,500	1,886	651.4	714.2
2046	363.70	472.20	278.69	361.83	178.4	232.7	1,500	1,961	649.7	723.9
2047	363.70	490.14	278.69	375.58	178.4	241.7	1,500	2,039	649.7	735.5
2048	363.70	508.76	278.69	389.85	178.4	250.9	1,500	2,119	649.7	748.3
2049	363.70	528.10	278.69	404.66	178.4	260.5	1,500	2,204	649.7	760.4
2050	363.70	548.17	278.69	420.04	178.4	270.4	1,500	2,292	649.7	773.3

All 12 totals I recorded match in every year from 2035 to 2039, so the change starts in 2040. Tax and spending both rise from 2040 because the tax base and the benefit rates both stop freezing. These rows measure the bug; they don't forecast the public finances.

Build time and CI cost

The longer indices add about 18,000 stored values, and every CountryTaxBenefitSystem and Simulation clones them.

CPU, median of 3 interleaved runs on one host	main 7ed5203	This branch	This branch + Core #631
Stored parameter entries	73,605	91,410	91,410
Clone of the processed tree	226 ms	309 ms	185 ms
New CountryTaxBenefitSystem	471 ms	542 ms	366 ms
Household Simulation plus household_net_income	2,044 ms	2,175 ms	2,014 ms
Memory per retained system	45.1 MB	50.7 MB	48.0 MB

My runs on a loaded host put the household slowdown at 6% to 11%. An independent run put it at 7.9% and found no slowdown in building a new system. The first build in a process also takes about 0.18 s longer, in process_parameters (0.35 s to 0.53 s of CPU, measured at 37591f4).

CI shows the same cost. At 3fbcd89 the Python shards took 66 to 75 minutes, against 51 to 70 minutes on three recent merge-queue runs, and the 75-minute limit cancelled shards 2/6 and 3/6, both at 99%. Test / YAML lost its runner about 7 minutes in on both runs of this branch, just after charge_parameters.yaml. Three YAML failures on merge-queue branches show the same runner shutdown 15 to 22 minutes in. The logs give a generic shutdown message with no out-of-memory record, so I infer memory from the 16.1 GiB local peak on main that #2742 reports and this branch's 13% larger retained systems.

Two changes outside this PR address those costs, and this PR should land after both:

• PolicyEngine/policyengine-core#631 replaces the deep copy of each entry's metadata with a shallow one. 99% of the entries hold an empty dict. On this branch it returns a household simulation to main's time.
• #2742 releases each YAML case's simulation and reformed systems.

This PR keeps the repeated annual records on main (54,000 of its 73,600 entries): _fiscal_year_conversion_years retains them on purpose, and the API metadata exposes them.

What else moves

• Fiscal 2039-40 bus fares. Three gov.dft.bus.local_bus_fares_index parameters use fiscal_year_blend, which reads the January 2040 index. main had no January 2040 value, so it understated that one fiscal year (London 257.75 against 259.10). Nothing else changes before 2040, and none of the recorded totals moves.
• Undated growth reforms. A scalar change to a growth series states that series out to 2100, so every index follows it to 2101. A dated change inside the data leaves the horizon at 2074, and one dated past it extends the index that far. The horizon tests pin all three.
• NI metadata. The API's metadata for five NI thresholds now lists values to 2074. test_live_parameter_metadata_preserves_legacy_scalar_records pins every rate in full and every threshold through 2039, where the legacy extract ends, and fails if a threshold falls after that.
• Downstream. uk-triple-lock pins economic_assumption_indices: [None, 2039] and the SHA-256 of these files in model_horizon.py, so its next PE-UK bump fails loudly until it re-audits. Its published results end at 2039-40. The API's UK year list reads PROJECTION_END_YEAR and the CGT projection, not the indices, so it doesn't widen.

Known limitation

Only 9 of the 46 growth series stated in the source tree reach 2073. The other 37 end between 2029 and 2036 and hold their final rate, as they did to 2039 on main, and the longer horizon compounds that rate for 35 more years. The ones that reach microsim inputs after 2032 include obr.mortgage_interest at 5.53% and obr.per_capita.mixed_income at 4.0%, so an index like mortgage interest reaches 36 times its base by 2074. These series need long-run paths of their own, which this PR leaves out of scope. The README now says so.

Invariants

1. Horizon: every index ends in the last year any growth series covers.
2. Compounding: each index is 1 in its first year, then the previous value times one plus that year's growth, rounded to 5 places (the earnings index keeps full precision). A shorter series holds its final rate.
3. Uprating: a parameter uprated by an index that moves after 2039 moves too, unless its value is zero.
4. Reforms: the horizon follows a reformed series.

Test plan

• policyengine_uk/tests/test_economic_assumption_horizon.py checks invariants 1 to 4, on the real tree and on 200 Hypothesis-generated growth trees of mixed lengths.
• Tests that pinned the 2039 end now read the horizon from the data, which extends the statutory threshold, Pension Credit, September CPI and Scottish carer checks to 2074. The carer reference names one intended exception: a rise landing exactly on a 2.5p tie may go either way, because the index keeps five decimal places. 28.75 x 1.02 does so in 2071, on the held 2% rate. I haven't verified whether the law requires the upper outcome on a tie.
• Synthetic growth trees in test_pension_credit_uprating.py and test_pension_age_projection_invariants.py end in 2039, so their lagged series reach 2040, and the checks run through 2040. Reforms they apply still reach the dependent forecasts.
• CI at 3fbcd89 recorded 11,235 Python tests, and only the NI metadata and cached-array tests failed; later commits fix both. CI didn't record 32 tests, either in the cancelled shards' last 1% or because main added them since; the 12 files holding them pass at b36cdf2 (2,851 tests). The 14 test files that cover this change and the new income tax properties pass at 478fc38 (650 tests). The 40 dataset tests a local offline run couldn't load passed in CI, apart from one expected failure.
• All 5,323 YAML cases pass locally at 3fbcd89. CI's YAML job lost its runner before it finished.
• For policy changes: no new YAML tests; this changes no rule.
• make format
• Changelog fragment changelog.d/derive-index-horizons.fixed.md

Reproducer

Reproducer: policyengine_uk/tests/test_economic_assumption_horizon.py::test_the_state_pension_keeps_rising_after_2039

axiom: n/a: microsim-only

🤖 Generated with Claude Code

[github-actions]

Aggregate impact on certified data: pass

Base 7ed52038aa against head 7f1d54dabc, 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 £-53,888,684 in total; 2026-27: 76 units below zero, a weighted £-55,774,885 in total; 2027-28: 76 units below zero, a weighted £-57,687,092 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 7ed52038aa	uk 2.166.0 (files 6090fe72afd4), core 3.33.12, py 3.13.18 aarch64	6e1a55d27c37	e90ddaeead60	2057.18s
head	#2756 merged into main 7f1d54dabc	uk 2.166.0 (files 82efe307df8c), core 3.33.12, py 3.13.18 aarch64	6e1a55d27c37	e90ddaeead60	2064.88s

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	£294.46bn	£315.23bn	£334.00bn	£349.45bn	£365.10bn	£383.16bn	£397.71bn
National Insurance (employee and self-employed)	£51.70bn	£54.14bn	£56.13bn	£57.73bn	£59.76bn	£61.64bn	£63.51bn
National Insurance (employer)	£148.71bn	£155.37bn	£160.88bn	£165.09bn	£172.06bn	£177.36bn	£182.57bn
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	£12.60bn	£13.15bn	£13.60bn	£14.11bn	£14.67bn	£15.24bn	£15.80bn
Student loan repayments	£7.82bn	£8.13bn	£8.39bn	£8.58bn	£8.79bn	£9.04bn	£9.29bn
VAT excluding private school fees	£249.37bn	£256.88bn	£266.66bn	£272.70bn	£278.97bn	£285.24bn	£291.59bn
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	£2.01bn	£2.09bn	£2.14bn	£2.21bn	£2.27bn	£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	£24.71bn	£24.59bn	£26.54bn	£26.58bn	£26.26bn	£25.53bn	£24.40bn
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	£4.40bn	£4.41bn	£4.42bn	£4.43bn	£4.44bn	£4.45bn
Council tax	£49.21bn	£52.16bn	£54.89bn	£57.95bn	£61.16bn	£64.47bn	£67.91bn
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	£36.20bn	£38.00bn	£39.46bn	£42.27bn	£43.25bn	£44.29bn
Stamp duty land tax on the household's own purchases	£6.88bn	£7.32bn	£7.66bn	£8.06bn	£8.47bn	£8.91bn	£9.35bn
Stamp duty land tax paid by companies	£4.72bn	£4.57bn	£5.29bn	£6.03bn	£6.37bn	£6.92bn	£7.45bn
Land transaction tax (Wales)	£0.07bn	£0.08bn	£0.08bn	£0.09bn	£0.10bn	£0.10bn	£0.11bn
Land and buildings transaction tax (Scotland)	£0.31bn	£0.32bn	£0.33bn	£0.35bn	£0.36bn	£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	£121.68bn	£125.92bn	£126.73bn	£129.50bn	£132.99bn	£136.66bn	£140.43bn
Pension Credit	£6.66bn	£7.03bn	£7.30bn	£7.51bn	£7.65bn	£7.84bn	£8.03bn
Winter Fuel Payment	£1.86bn	£1.85bn	£1.79bn	£1.77bn	£1.78bn	£1.78bn	£1.78bn
Pension Age Winter Heating Payment (Scotland)	£0.19bn	£0.20bn	£0.20bn	£0.21bn	£0.21bn	£0.22bn	£0.22bn
Universal Credit	£75.48bn	£80.52bn	£83.04bn	£85.11bn	£86.31bn	£87.90bn	£88.58bn
Housing Benefit	£8.56bn	£8.89bn	£9.24bn	£9.48bn	£9.72bn	£9.99bn	£10.27bn
Council Tax Reduction	£2.07bn	£2.20bn	£2.31bn	£2.45bn	£2.58bn	£2.72bn	£2.86bn
Employment and Support Allowance (income-related)	£0.79bn	£0.82bn	£0.84bn	£0.86bn	£0.88bn	£0.90bn	£0.92bn
Employment and Support Allowance (contribution-based)	£5.20bn	£5.37bn	£5.56bn	£5.69bn	£5.82bn	£5.95bn	£6.09bn
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	£0.31bn	£0.31bn	£0.32bn	£0.33bn	£0.34bn
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	£26.95bn	£28.03bn	£29.05bn	£30.09bn	£30.75bn	£31.51bn	£32.21bn
Disability Living Allowance	£7.49bn	£7.79bn	£8.07bn	£8.36bn	£8.55bn	£8.76bn	£8.95bn
Attendance Allowance	£8.68bn	£9.03bn	£9.36bn	£9.69bn	£9.90bn	£10.15bn	£10.38bn
Carer's Allowance	£4.48bn	£4.66bn	£4.83bn	£5.00bn	£5.11bn	£5.23bn	£5.35bn
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	£0.04bn	£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	£0.54bn	£0.55bn	£0.56bn	£0.58bn	£0.59bn
Armed Forces Compensation Scheme	£0.61bn	£0.63bn	£0.65bn	£0.66bn	£0.68bn	£0.69bn	£0.71bn
War Widow's or Widower's Pension	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Child Benefit	£16.19bn	£16.82bn	£17.39bn	£18.00bn	£18.39bn	£18.84bn	£19.25bn
Scottish Child Payment	£0.49bn	£0.52bn	£0.53bn	£0.56bn	£0.57bn	£0.57bn	£0.57bn
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	£3.41bn	£3.54bn	£3.62bn	£3.70bn	£3.78bn	£3.87bn
Statutory Paternity Pay	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Statutory Sick Pay	£1.12bn	£1.16bn	£1.20bn	£1.23bn	£1.26bn	£1.29bn	£1.32bn
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	£0.71bn	£0.73bn	£0.75bn	£0.76bn	£0.78bn
Widowed Parent's Allowance	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Tax-Free Childcare	£0.56bn	£0.57bn	£0.58bn	£0.59bn	£0.61bn	£0.62bn	£0.59bn
Extended childcare entitlement	£2.99bn	£3.50bn	£3.62bn	£3.75bn	£3.83bn	£3.92bn	£4.01bn
Universal childcare entitlement	£2.06bn	£2.22bn	£2.29bn	£2.38bn	£2.44bn	£2.51bn	£2.56bn
Targeted childcare entitlement	£0.50bn	£0.51bn	£0.52bn	£0.54bn	£0.55bn	£0.57bn	£0.56bn
Childcare Offer for Wales	£0.26bn	£0.28bn	£0.28bn	£0.29bn	£0.30bn	£0.31bn	£0.32bn
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	£203.89bn	£204.30bn	£204.56bn	£204.91bn	£205.34bn	£205.85bn	£206.35bn
State education spending	£0.02bn	£0.02bn	£0.02bn	£0.02bn	£0.02bn	£0.02bn	£0.02bn
Transport subsidy spending	£25.05bn	£25.10bn	£25.14bn	£25.18bn	£25.23bn	£25.30bn	£25.36bn
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	11,264k	11,145k	10,819k	10,700k	10,723k	10,750k	10,776k
Pension Credit	1,486k	1,480k	1,474k	1,455k	1,453k	1,455k	1,464k
Winter Fuel Payment	7,844k	7,783k	7,473k	7,375k	7,391k	7,409k	7,427k
Pension Age Winter Heating Payment (Scotland)	803k	802k	800k	797k	799k	801k	802k
Universal Credit	6,342k	6,347k	6,350k	6,316k	6,298k	6,291k	6,246k
Housing Benefit	1,249k	1,245k	1,246k	1,229k	1,229k	1,229k	1,232k
Council Tax Reduction	3,176k	3,195k	3,200k	3,215k	3,224k	3,235k	3,242k
Employment and Support Allowance (income-related)	71k	71k	71k	71k	71k	71k	71k
Employment and Support Allowance (contribution-based)	719k	720k	721k	722k	724k	726k	728k
Jobseeker's Allowance (income-based)	0k	0k	0k	0k	0k	0k	0k
Jobseeker's Allowance (contribution-based)	67k	67k	67k	67k	67k	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	3,567k	3,575k	3,579k	3,585k	3,593k	3,602k	3,611k
Disability Living Allowance	1,291k	1,294k	1,296k	1,298k	1,300k	1,304k	1,307k
Attendance Allowance	1,695k	1,698k	1,700k	1,703k	1,707k	1,711k	1,715k
Carer's Allowance	1,034k	1,037k	1,038k	1,040k	1,042k	1,044k	1,046k
Carer Support Payment (Scotland)	71k	71k	71k	72k	72k	72k	72k
Carer's Allowance Supplement (Scotland)	0k	71k	71k	72k	72k	72k	72k
Severe Disablement Allowance	4k	4k	4k	4k	4k	4k	4k
Industrial Injuries Disablement Benefit	137k	137k	137k	138k	138k	138k	139k
Armed Forces Compensation Scheme	93k	93k	94k	94k	94k	94k	94k
War Widow's or Widower's Pension	0k	0k	0k	0k	0k	0k	0k
Child Benefit	8,123k	8,120k	8,120k	8,130k	8,145k	8,161k	8,178k
Scottish Child Payment	351k	352k	352k	355k	353k	351k	340k
Two Child Limit Payment (Scotland, counterfactual)	0k	0k	0k	0k	0k	0k	0k
Healthy Start vouchers	200k	200k	200k	201k	201k	201k	202k
Maternity Allowance	0k	0k	0k	0k	0k	0k	0k
Statutory Maternity Pay	333k	333k	334k	334k	335k	336k	337k
Statutory Paternity Pay	0k	0k	0k	0k	0k	0k	0k
Statutory Sick Pay	181k	182k	182k	182k	182k	183k	183k
Sure Start Maternity Grant	26k	26k	26k	26k	26k	26k	26k
Bereavement Support Payment	98k	98k	98k	98k	98k	99k	99k
Widowed Parent's Allowance	0k	0k	0k	0k	0k	0k	0k
Tax-Free Childcare	1,043k	1,027k	1,021k	1,024k	1,029k	1,026k	1,011k
Extended childcare entitlement	795k	800k	804k	806k	809k	814k	814k
Universal childcare entitlement	1,071k	1,072k	1,074k	1,076k	1,079k	1,089k	1,090k
Targeted childcare entitlement	165k	156k	154k	154k	155k	155k	150k
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	98k	99k	99k	99k	99k
Adult Dependants' Grant	18k	18k	12k	12k	12k	12k	12k
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	£892.00bn	£935.14bn	£979.55bn	£1,013.85bn	£1,052.14bn	£1,089.13bn	£1,122.37bn
Government spending	£529.38bn †	£543.55bn †	£550.93bn †	£559.77bn †	£567.54bn †	£576.30bn †	£584.05bn †
Government balance, each receipt once	£362.62bn †	£391.59bn †	£428.62bn †	£454.08bn †	£484.59bn †	£512.83bn †	£538.32bn †
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	£892.00bn	£935.14bn	£979.55bn	£1,013.85bn	£1,052.14bn	£1,089.13bn	£1,122.37bn
household_tax	£491.97bn	£520.87bn	£549.93bn	£573.92bn	£598.90bn	£624.26bn	£645.90bn
pre_budget_change_household_tax	£484.15bn	£512.74bn	£541.54bn	£564.86bn	£589.61bn	£614.72bn	£636.09bn
gov_spending	£529.38bn †	£543.55bn †	£550.93bn †	£559.77bn †	£567.54bn †	£576.30bn †	£584.05bn †
household_benefits	£529.38bn †	£543.55bn †	£550.93bn †	£559.77bn †	£567.54bn †	£576.30bn †	£584.05bn †
gov_balance	£362.62bn †	£391.59bn †	£428.62bn †	£454.08bn †	£484.59bn †	£512.83bn †	£538.32bn †

Household income totals: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Household market income	£1,637.96bn	£1,702.77bn	£1,757.35bn	£1,806.41bn	£1,855.97bn	£1,912.43bn	£1,970.44bn
Household net income	£1,636.69bn †	£1,685.25bn †	£1,716.89bn †	£1,749.83bn †	£1,781.14bn †	£1,819.80bn †	£1,862.66bn †
Household net income (HBAI definition)	£1,449.57bn	£1,497.73bn	£1,532.81bn	£1,567.22bn	£1,600.03bn	£1,638.06bn	£1,679.23bn

Population: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
People	69,245k	69,383k	69,473k	69,592k	69,738k	69,912k	70,080k
Benefit units	35,110k	35,181k	35,226k	35,286k	35,360k	35,449k	35,534k
Households	31,046k	31,108k	31,149k	31,201k	31,267k	31,345k	31,420k

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	16.3%	15.6%	16.4%	16.3%	16.5%	16.5%	16.6%
Absolute poverty, before housing costs: children	24.7%	22.3%	23.3%	22.9%	23.1%	23.2%	23.4%
Absolute poverty, before housing costs: working-age adults	14.1%	13.9%	14.7%	14.7%	14.8%	14.8%	14.9%
Absolute poverty, before housing costs: pensioners	13.7%	13.5%	14.0%	13.9%	14.0%	13.9%	13.9%
Absolute poverty, after housing costs: everyone	21.6%	21.1%	22.0%	22.5%	22.7%	23.0%	23.3%
Absolute poverty, after housing costs: children	33.3%	31.3%	32.2%	32.4%	32.5%	33.0%	33.9%
Absolute poverty, after housing costs: working-age adults	19.9%	19.9%	20.8%	21.5%	21.8%	22.0%	22.2%
Absolute poverty, after housing costs: pensioners	12.7%	12.6%	13.1%	13.2%	13.3%	13.4%	13.5%
Relative poverty, before housing costs: everyone	17.0%	16.3%	16.4%	16.3%	16.3%	16.3%	16.7%
Relative poverty, before housing costs: children	25.9%	23.4%	23.3%	22.9%	22.8%	22.9%	23.7%
Relative poverty, before housing costs: working-age adults	14.5%	14.3%	14.6%	14.7%	14.7%	14.7%	15.0%
Relative poverty, before housing costs: pensioners	14.5%	14.7%	13.9%	13.9%	13.8%	13.9%	14.0%
Relative poverty, after housing costs: everyone	21.4%	21.0%	21.2%	21.3%	21.3%	21.5%	21.7%
Relative poverty, after housing costs: children	33.1%	31.1%	31.1%	31.0%	31.1%	31.2%	31.7%
Relative poverty, after housing costs: working-age adults	19.9%	19.8%	20.2%	20.4%	20.5%	20.6%	20.8%
Relative poverty, after housing costs: pensioners	12.5%	12.4%	12.2%	11.7%	11.7%	11.8%	12.0%

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	11,278k	10,837k	11,403k	11,358k	11,478k	11,506k	11,643k
Absolute poverty, before housing costs: children	3,688k	3,332k	3,496k	3,437k	3,477k	3,499k	3,545k
Absolute poverty, before housing costs: working-age adults	5,965k	5,921k	6,308k	6,354k	6,417k	6,426k	6,517k
Absolute poverty, before housing costs: pensioners	1,624k	1,584k	1,599k	1,568k	1,583k	1,580k	1,581k
Absolute poverty, after housing costs: everyone	14,944k	14,662k	15,296k	15,679k	15,862k	16,047k	16,331k
Absolute poverty, after housing costs: children	4,975k	4,689k	4,832k	4,863k	4,898k	4,986k	5,125k
Absolute poverty, after housing costs: working-age adults	8,463k	8,491k	8,965k	9,325k	9,464k	9,549k	9,669k
Absolute poverty, after housing costs: pensioners	1,506k	1,482k	1,500k	1,491k	1,500k	1,513k	1,537k
Relative poverty, before housing costs: everyone	11,750k	11,332k	11,389k	11,348k	11,358k	11,410k	11,702k
Relative poverty, before housing costs: children	3,872k	3,504k	3,496k	3,434k	3,431k	3,451k	3,577k
Relative poverty, before housing costs: working-age adults	6,159k	6,103k	6,301k	6,349k	6,363k	6,388k	6,540k
Relative poverty, before housing costs: pensioners	1,720k	1,724k	1,592k	1,565k	1,563k	1,571k	1,585k
Relative poverty, after housing costs: everyone	14,849k	14,583k	14,728k	14,809k	14,885k	15,005k	15,219k
Relative poverty, after housing costs: children	4,942k	4,664k	4,660k	4,663k	4,681k	4,702k	4,798k
Relative poverty, after housing costs: working-age adults	8,426k	8,460k	8,679k	8,821k	8,877k	8,964k	9,056k
Relative poverty, after housing costs: pensioners	1,482k	1,459k	1,389k	1,325k	1,327k	1,340k	1,366k

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	0.3080	0.3057	0.3063	0.3062	0.3068	0.3073	0.3089

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	£17,681 †	£17,895 †	£17,904 †	£18,146 †	£18,308 †	£18,581 †	£18,739 †
Decile 2: mean household_net_income per household	£27,939 †	£28,874 †	£28,683 †	£29,083 †	£29,354 †	£29,679 †	£30,165 †
Decile 3: mean household_net_income per household	£34,320 †	£35,455 †	£36,108 †	£36,626 †	£37,218 †	£37,722 †	£38,220 †
Decile 4: mean household_net_income per household	£38,933 †	£40,603 †	£41,873 †	£42,783 †	£43,423 †	£43,928 †	£44,548 †
Decile 5: mean household_net_income per household	£43,239 †	£45,442 †	£45,787 †	£46,995 †	£47,729 †	£48,921 †	£50,229 †
Decile 6: mean household_net_income per household	£47,927 †	£49,126 †	£50,887 †	£51,728 †	£52,601 †	£54,202 †	£55,188 †
Decile 7: mean household_net_income per household	£55,662 †	£56,509 †	£57,442 †	£57,965 †	£59,083 †	£59,211 †	£60,675 †
Decile 8: mean household_net_income per household	£68,789 †	£70,704 †	£71,779 †	£73,356 †	£73,952 †	£75,362 †	£77,248 †
Decile 9: mean household_net_income per household	£78,890 †	£80,992 †	£82,907 †	£84,246 †	£85,584 †	£87,169 †	£89,597 †
Decile 10: mean household_net_income per household	£117,005 †	£120,262 †	£122,221 †	£124,681 †	£126,775 †	£129,108 †	£131,486 †

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	£6.41bn	£6.66bn	£6.64bn	£6.86bn	£7.04bn	£7.26bn	£7.48bn
Raise higher rate by 1pp	£3.61bn	£3.87bn	£4.00bn	£4.21bn	£4.43bn	£4.71bn	£4.83bn
Raise personal allowance by ~800GBP/year	£-3.80bn	£-3.92bn	£-3.98bn	£-4.09bn	£-4.17bn	£-4.21bn	£-1.94bn
Raise child benefit by 25GBP/week per additional child	£-1.99bn	£-1.75bn	£-1.55bn	£-1.39bn	£-1.30bn	£-1.17bn	£-1.06bn
Reduce Universal Credit taper rate to 20%	£-20.77bn	£-21.32bn	£-21.78bn	£-22.02bn	£-22.36bn	£-22.77bn	£-22.96bn
Raise Class 1 main employee NICs rate to 10%	£10.89bn	£11.30bn	£11.71bn	£12.01bn	£12.31bn	£12.62bn	£13.01bn
Raise VAT standard rate by 2pp	£24.89bn	£25.71bn	£26.63bn	£27.24bn	£27.87bn	£28.50bn	£29.14bn
Raise additional rate by 3pp	£2.90bn	£3.15bn	£3.22bn	£3.42bn	£3.61bn	suppressed	suppressed
Raise the Universal Credit standard allowance by 10%	£-3.06bn	£-3.18bn	£-3.27bn	£-3.35bn	£-3.44bn	£-3.48bn	£-3.50bn
Raise the State Pension by 10%	£-7.78bn	£-8.01bn	£-7.99bn	£-8.14bn	£-8.42bn	£-8.55bn	£-8.89bn

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	£6.55bn	£6.86bn	£6.80bn	£7.01bn	£7.21bn	£7.44bn	£7.66bn
Raise higher rate by 1pp: change in income_tax	£3.61bn	£3.92bn	£4.01bn	£4.23bn	£4.45bn	£4.72bn	£4.84bn
Raise personal allowance by ~800GBP/year: change in income_tax	£-3.93bn	£-4.07bn	£-4.16bn	£-4.25bn	£-4.32bn	£-4.38bn	£-1.75bn
Raise child benefit by 25GBP/week per additional child: change in child_benefit	£2.33bn	£2.14bn	£1.94bn	£1.76bn	£1.65bn	£1.52bn	£1.40bn
Reduce Universal Credit taper rate to 20%: change in universal_credit	£20.74bn	£21.31bn	£21.77bn	£22.02bn	£22.34bn	£22.74bn	£22.96bn
Raise Class 1 main employee NICs rate to 10%: change in national_insurance	£11.15bn	£11.63bn	£12.00bn	£12.29bn	£12.61bn	£12.94bn	£13.31bn
Raise VAT standard rate by 2pp: change in vat	£24.69bn	£25.51bn	£26.42bn	£27.03bn	£27.65bn	£28.28bn	£28.91bn
Raise additional rate by 3pp: change in income_tax	£2.90bn	£3.15bn	£3.22bn	£3.42bn	£3.62bn	suppressed	suppressed
Raise the Universal Credit standard allowance by 10%: change in universal_credit	£3.06bn	£3.19bn	£3.29bn	£3.37bn	£3.44bn	£3.50bn	£3.53bn
Raise the State Pension by 10%: change in state_pension	£10.68bn	£11.17bn	£11.28bn	£11.60bn	£12.04bn	£12.47bn	£12.97bn

[MaxGhenis]

Hand-off to the UK hub at head 478fc381bbab11e52be2e1648a496250ce1e0eba.

GPT-6.1 Sol (subfleet run --task review --tier hard) approved this head with no findings. Its report sits at ~/reviews/uk-hub/pr-2756/reviews/review_478fc381b.md, beside the earlier rounds, and the State Pension runs, cost probes and CI logs sit in the same folder.

Lint, Changes, Changelog fragments, both documentation builds, the release build, Fix evidence and the four smoke imports pass at this head. Python 1/6 to 6/6, YAML and Aggregate impact hadn't finished at 01:33Z on 31 October.

At 3fbcd896f the 75-minute limit cancelled Python 2/6 and 3/6 at 99%, and YAML lost its runner about 7 minutes in. Either can recur until these land:

• Release each YAML case's simulation and its file's reformed systems #2742 releases each YAML case's simulation and reformed systems, and it stays first in the hub's order.
• Share nested metadata values between parameter clones policyengine-core#631 returns a household simulation on this branch to main's time. The UK lock needs a bump from Core 3.33.12 to pick it up, and the US + core hub owes a landing plan by 22:57Z on 31 October.

This PR leaves test-suite.yaml alone. If Core #631 slips by more than a few days, the UK hub decides on a timeout change in its own PR.

d2161 stops any agent merging or enqueueing this PR. No published number moves, so it needs no sign-off from Max. d2222 holds the separate call on long-run paths for the 37 short growth series.

Three other pieces of work overlap this PR:

• Round projected State Pension weekly rates to the nearest 5p each April #2751 rounds the State Pension rates in this PR's table and adds UNROUNDED_INDICES to the same builder, so whichever lands second refreshes the table or resolves the builder.
• Apply each growth index's first listed year #2693 edits the README, lagged_series.py, yoy_growth.yaml and the private pension file, and its test loops to 2040.
• uk-triple-lock pins these files, so its next PE-UK bump fails until it re-audits.

🤖 Generated with Claude Code