Set UK road-fuel and energy levels in the LCFS stage on a calendar-2024 basis (#1113)

[juaristi22]

Summary

Part of #1113 and of #1123 (item 3). The UK LCFS stage now sets household road fuel and domestic energy at their published levels, at calendar-2024 prices, instead of leaving the calibration weights to reach them. The rows whose gap is not a weight question become measured diagnostics. This follows María's rulings of 2026-10-08 (D1–D3), plus two of 2026-10-09: the ONS road-fuel row is bound, and every LCFS spend column sits on one calendar-2024 basis.

• Calibration rows. obr.vat, ons.household_electricity_expenditure, ons.household_gas_expenditure and obr.fuel_duties_cars move to the measure-exclusion register. They are still measured on every evaluation, and the entries expire 2027-01-08. The contract binds a new household-scope row in their place: ons.household_road_fuel_expenditure (ONS Consumer Trends 07.2.2, calendar 2025, measured as petrol plus diesel spend).
• LCFS stage. Three declared steps:
  • redraw_zero_road_fuel gives every flagged fuel-car household a positive fuel spend;
  • level_road_fuel scales petrol and diesel to ONS 07.2.2 for 2024, less the donor's other-fuels share;
  • recompose_from_remainder writes housing and transport around their levelled parts.
• Calendar-2024 basis. Energy is priced at QEP's calendar-2024 averages and levelled to the DESNZ volume over the four quarters of 2024. Each area's bus yield is re-priced to 2024 by its fares index. policyengine-uk can then project every column from the H5's year.
• Gates. Four new release-blocking stage-health gates check the receipts: road_fuel_incidence, road_fuel_level, recomposed_totals and consumption_basis.
• Diagnostics (report-only):
  • uk_diagnostics.consumption_drift: the levelled totals and shares at design and final weights;
  • division_capture in the stage receipt: each COICOP division against ONS Consumer Trends;
  • the litres audit: each fuel against its cars share of road use.
• Feed. The UK Chronicle feed is re-pinned to 1ee7dfe (UK consumption-tax facts: Consumer Trends for every COICOP division, and road fuel by vehicle type and fuel (PolicyEngine/microcosm#1113, PolicyEngine/microcosm#1123) chronicle#322 via Expand UK consumption-tax expenditure and road fuel facts chronicle#323, 352,549 rows), which brings Consumer Trends by division and DESNZ road fuel by vehicle type and fuel. No compiled target value moves on either surface, and the three compile-parity receipts are unchanged.

Receipts, findings and rulings are in experiments/1113-consumption-tax-levels-receipts.md.

Why the levels belong to the stage

On #1121's head calibration (policyengine-uk 2.122.2, 1,167 rows):

• obr.vat reads +24.7% at design weights, against a 25% bound. Its level is the engine's microdata_vat_coverage factor (0.38, with no recorded derivation; policyengine-uk#1996), not a weight question.
• The ONS electricity and gas rows sit below the unit cost of the DESNZ volume at QEP prices, so they are a published-source residual.
• obr.fuel_duties_cars reads −34.5% at design weights. It is a fiscal-year duty total that includes business use of cars. The LCFS diary records about a quarter less road fuel than ONS, and a third of fuel-car households show no fuel purchase in the two-week diary.
• Closing these rows through the weights distorts the frame. The gas-connected share fell from 84.5% to 78.9%, petrol rose 21% and diesel 34%.
• Masking all four rows in a re-solve of the 2026-09-30 national problem cost the other 1,086 rows nothing: 98.5% within 10%, against 98.4%.

Stage-only measurements

These re-run lcfs_consumption on #1121's head-r3 spine (63,956 households), before the rebase. All seven lcfs stage-health gates pass.

• Road fuel. No flagged fuel-car household is left at zero fuel (33.2% before the redraw). Petrol plus diesel is levelled to £36.89bn: ONS 07.2.2 for 2024 (£37.03bn) less the donor's 0.37% other-fuels share.
• Energy. Electricity is £29.5bn and gas £19.2bn at calendar-2024 prices, with 84.6% of households connected to gas.
• Totals. No household's housing or transport total is below its levelled parts (2.7% and 1.8% were before). Consumption across the twelve divisions moves from £979.0bn to £971.4bn (−0.8%).
• Division capture. The frame's twelve divisions are 72.8% of ONS's 2024 spending in survey scope; the donor's own diary is 58.5%.
  • Housing reads 1.059. D1's energy level is £8.0bn of its £9.7bn excess.
  • Furnishings read 1.251: the frame draws 66% more per household than the donor. That is not investigated here.
• Litres audit. Against HMRC clearances times DESNZ's cars share of each fuel, petrol reads 1.011 and diesel 0.709.

Not in this PR

• The national remeasure (R1). One spine build and one national line run next, on the policyengine-uk version Microcosm locks then. The VAT, fuel-duty and energy engine fixes are open in Re-average fuel duty and other blended rates after mid-year reforms policyengine-uk#2185, Put road-fuel litre divisors on DESNZ pump prices policyengine-uk#2186, Split VAT grossing into household share and survey coverage policyengine-uk#2187 and Model the temporary 0% VAT on GB domestic electricity policyengine-uk#2189.
• Rebinding obr.vat. That waits until policyengine-uk splits its VAT factor (policyengine-uk#1996).
• The furnishings and health over-draw surfaced by the division capture.

Testing

• Targeted engine-free tests for each commit's surface. At the head, before the rebase, a broad funnel of 1,613 tests and a sweep of the remaining touched-surface files (1,251 tests) passed. The skips are tests that need the licensed LCFS tabs or the US extra.
• During the rebase onto 7f235941c, a check ran after every commit. Each commit loads the UK spec, has a current release-input coverage manifest, and has current gate digests mirrored in microcosm-data.
• The charter-H2 spine fixture is regenerated once, at the head. Only the stage contract hashes move: lcfs_consumption's, and those of the ten stages declaring a vendored resource the re-pin restamped. The commits before that one fail test_h2_uk_spine_parity on their own.

🤖 Generated with Claude Code

[vahid-ahmadi]

Automated review pass (Claude Code, high effort) — round 1 at 2e32d7bd

Verdict: nothing blocks this. The stage steps are sound, declared and gated, and the four rows it moves out of the fit are justified and signed. Two should-fixes on the register wording and the bound row, and one to note for the engine side before the national remeasure.

What checks out

• level_road_fuel is one factor on petrol and diesel at prior weights, so the drawn mix and each household's relative spend are kept (lcfs_consumption.py:1151-1182). The other-fuels share comes from the donor's own c72213, and the step refuses a fiscal-year level or a share outside [0, 1).
• redraw_zero_road_fuel is seeded, identity-keyed and redraws only flagged households that drew zero, so households without a fuel car stay at zero.
• recompose_from_remainder refuses a declaration that differs from the parents and components it recomposes, and floors the remainder at zero.
• Calendar 2024 is applied everywhere: energy sums the four Energy Trends quarters of 2024 (energy_pricing.py, period_quarters); road fuel levels to ONS 07.2.2 for 2024; bus yields are re-priced to 2024. The consumption_basis gate holds every level step to that year.
• Four new release_blocking gates (road_fuel_incidence, road_fuel_level, recomposed_totals, consumption_basis) are in gates.json, with digests mirrored.
• The four exclusions are signed, carry a tracking issue, an adjudication with receipts and an expiry (2027-01-08), and stay measured through tools/diagnose_uk_consumption_taxes.py.
• The Chronicle pin 1ee7dfe is the merge commit of chronicle#323 on main. The selectors resolve 07.2.2 as text, and the 217 restated rows keep their values under the new keys.
• Tests: the 17 touched test files pass locally (778 passed, 6 skipped). Against the base 7f235941, the new stage-health tests fail and the new diagnostics test doesn't import, so they cover the change.

Should

1. The electricity and gas exclusion reasons describe the old basis (calibration_measure_exclusions.json:590, :599). They say the stage sets spend from "Energy Trends FY2024-25 domestic volume at QEP FY2024-25 average prices", but the stage now uses calendar 2024 (the 2026-10-09 ruling), and the quoted ratios (0.90, 0.81) were measured on the fiscal-year basis. Restate both reasons on calendar 2024 and re-quote the ratios, so the register matches what the stage does.
2. The bound row compares petrol plus diesel with all of 07.2.2 (uk_population_targets.json, ons.household_road_fuel_expenditure). The stage levels to 07.2.2 less the donor's other-fuels share (0.37%), but the target is the full class, so calibration pulls about 0.4% toward fuel buyers to close a gap that is only scope. Either scale the target by the same share the stage uses, or record it as a known 0.4% offset in the binding notes and the receipts.
3. Non-residents' spending inside the bound row. The notes say 07.2.2 is on the domestic concept and no bridge is applied. That's fine as a choice, but the frame is residents only, so the row is an upper bound. Add one line with the size of the effect (or that ONS gives no split), so a later reader knows which way it leans.

Nits

4. The model year: policyengine-uk reads the H5's 2024 as fiscal 2024-25, while the frame is priced at calendar 2024, about a quarter apart. Worth one sentence in the stage notes, since every levelled column inherits it.
5. If the LCFS diary has a line for vehicle electricity inside 07.2.2, it should sit with c72213 in the other-fuels share; otherwise a sentence saying it doesn't exist.

Knock-on for policyengine-uk

• #2186 (DESNZ litre divisors): still holds. Its divisors are DESNZ calendar-year averages, the same basis this stage prices road fuel on, and its spending proxy is derived to keep litres on the volume path whatever the level. What moves is the level: petrol plus diesel for 2024 goes from £34.81bn on the certified release to £36.89bn here (+6.0%), so litres and fuel duty rise by the same 6%, about 25.6bn litres in 2024 and about £13.3bn of duty in 2025. That matches the register's −8.1% against the OBR cars line. The new ONS row will read about −1% at design weights, because the engine's 2024-to-2025 spending growth (−6.2%) is a little below ONS's (−5.2%).
• #2187 (VAT coverage split): the 0.67 coverage was derived on the certified release. Here total consumption is 0.8% lower and energy is levelled separately, which by itself moves coverage to about 0.665, still 0.67 to two places, but it should be re-derived on the R1 remeasure. Once #2187 is in the locked version, the obr.vat exclusion's own retire condition is met ("rebind when a locked policyengine-uk splits the factor"), and on the certified release the split factor put VAT within 0.4% of OBR.
• #2189 (electricity and gas VAT base): energy here is priced at QEP calendar-2024 average prices including VAT, so the 5/105 extraction is still right. #2189's description says the bills are at Ofgem cap rates; that should say QEP average prices paid. With electricity at £29.5bn and gas at £19.2bn, domestic energy VAT is about £2.32bn, against about £2.02bn on the certified release and HMRC's implied £2.33bn, and the 2026-27 zero-rate cost rises from about £0.62bn to roughly £0.70bn.