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Refresh social rent target to EHS 2024-25 vintage - #455
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The three housing targets are all set for 2025, but the social rent basis used the English Housing Survey 2023-24 mean (GBP 118/week) while the private rent basis used ONS PRHI from February 2026. Anchoring targets for the same year to vintages two years apart understated the social basis by roughly 10% against its own target year. EHS 2024-25 reports GBP 129/week (local authority GBP 120, housing association GBP 134), moving the target from ~GBP 30.7bn to ~GBP 33.5bn. Adds a test pinning the implied weekly mean to the published EHS figure, so the target cannot silently go stale against a newer release again, and documents on the module that these are totals only: at dataset 1.40.3 the private target is met at 1.04x with 6.99m renters at GBP 256/week against a basis of 5.4m at GBP 317/week, so a count error and an offsetting mean error cancel and the target validates nothing. This does not by itself correct modelled social rents, which sit 1.55x above the target (5.77m households at GBP 159/week). That is a calibration convergence question tracked in #454. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The previous test asserted that _SOCIAL_RENT_TOTAL / 5.0e6 / 52 fell between 125 and 135 - recomputing the constant from the constant. It could not detect a newer EHS release, which is what its docstring and the PR body claimed. Replaced with an explicit pin on named basis components, documented as a review guard rather than a staleness check. Also drops unrelated uv.lock churn from the branch. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
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Pushed two corrections to this PR after an independent audit found problems with it. 1. The staleness test did not test staleness. 2. Dropped unrelated Corrections to the PR descriptionDirection of effect, which I failed to state. Raising the target from GBP 30.7bn to GBP 33.5bn moves it toward the modelled GBP 47.6bn (1.55x → 1.42x). On the next rebuild the calibration will push modelled social rents slightly up, marginally worsening the over-capping that #454 exists to fix. My claim that "refreshing the target does not move the data" holds only until a rebuild. Stale residual figures. The "what this does not fix" section quotes 1.55x against a GBP 118/week basis — that is the state before this PR. Post-merge it is ~1.42x against GBP 129/week. Vintages are still not aligned. The stated goal was targets anchored to the same year; after this PR it is EHS 2024-25 against ONS PRHI February 2026 for a 2025 target — still about a year apart, with the private side now the more anomalous of the two. "The private rent target validates nothing" was too strong. Household-count targets on the same population already exist ( Context that has emerged sinceThe deeper causes are now filed separately and are larger than this PR: #456 (the loss function under-penalises overshoots; the gradient peaks at ratio 2.0 and declines, and This PR remains a small, correct provenance fix. It is not a fix for the 1.55x miss, and I would not want it read as one. |
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@MaxGhenis review request — small provenance fix, but please read the corrections comment above before merging. Two things I would want a second opinion on:
Happy for this to wait behind those if you would rather not move the basis twice. |
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Calibration fit against the base build: pass
A drop of more than 2.0% fails. Notes
National targets in a worse error band on the head (4)
Flags are for review: builds of the same code move 2 to 12 national targets to a worse band (#598). Bands are of |estimate / target - 1|; no target's estimate or error is published. Income distribution and single ages against the base build: passHBAI FYE 2025 (DWP), period 2024: equivalised income in £ a week, rates and Gini in per cent. A value outside HBAI's 95% interval is marked (outside).
FlagsNone. These measures report and flag but do not fail yet: their same-code spread is unmeasured (#598). Aggregate impact of the data change: passBase dataset Checks: 0 broken by this change, 4 failing on both sides, 0 fixed. Moves flagged for review: 25 (thresholds in Notes
Moves flagged for review
Receipts by tax head
Spending by benefit and service
Caseloads
Government balance, each component counted once
Model totals
Components the model counts twice
Household income totals
Population
Poverty rates
People in poverty
Inequality
Mean household net income in each side's own deciles
Standard reform costings (change in gov_balance)
Standard reforms: change in each reform's target
Household net income by decileThe datasets hold different households, so households are not matched; compare the mean income in each side's own deciles. Checks failing on both base and head (4)
Counted-once checkCounted-once check not run: not requested. Provenance
Base dataset: Head dataset: Receipts by tax head: head levels
Spending by benefit and service: head levels
Caseloads: head levels
Government balance, each component counted once: head levels
Model totals: head levels
Components the model counts twice: head levels
Household income totals: head levels
Population: head levels
Poverty rates: head levels
People in poverty: head levels
Inequality: head levels
Mean household net income in each side's own deciles: head levels
Standard reform costings (change in gov_balance): head levels
Standard reforms: change in each reform's target: head levels
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Partial fix for #454.
The problem
All three housing targets are set for 2025, but they are anchored to vintages two years apart:
housing/rent_privatehousing/rent_socialEHS 2024-25 has since published a GBP 129/week mean social rent (local authority GBP 120, housing association GBP 134), so the social target was roughly 10% stale against its own target year.
The change
Social basis moves to GBP 129/week, taking the target from ~GBP 30.7bn to ~GBP 33.5bn, with the reference updated to the EHS 2024-25 chapter. Adds a test pinning the implied weekly mean to the published figure so the target cannot silently go stale against a newer EHS release again.
Also documents a limitation found while investigating #454: these are totals only, so a household-count error and an offsetting mean error cancel. At dataset 1.40.3 the private target is met at 1.04x — but with 6.99m renters at GBP 256/week against a basis of 5.4m at GBP 317/week. Count and mean are each wrong by ~30% and ~19% in opposite directions and the total matches anyway, so
housing/rent_privatecurrently validates nothing. Pairing the totals with count constraints, or targeting mean rent by tenure, would fix that; I have left it out here because it changes the loss matrix and cannot be verified without a full rebuild.What this does not fix
Modelled social rents remain 1.55x the target (5.77m households at GBP 159/week against a basis of 5.0m at GBP 118/week; 1.15x on count, 1.35x on mean). Refreshing the target does not move the data — that is a calibration convergence question, and it is what makes the benefit cap apply to 222k households against DWP's 111k (PolicyEngine/policyengine-uk#1818). Both remain open on #454.
Testing
test_housing_targets.pypasses (10 tests). No pipeline or dataset rebuild involved.