PolicyEngine UK Data

PolicyEngine's project to build accurate UK household survey data.

Local dataset builds

For a full local dataset build:

1. Ensure the private prerequisite folders exist under policyengine_uk_data/storage/.
2. Use Python 3.13. Python 3.14 currently fails while loading PyTables/Blosc2 in this repo.
3. Prefer the sibling policyengine-uk checkout when building locally, because the published wheel in your active environment may not expose all variables required by the data pipeline.

If ../policyengine-uk exists, you can run:

make data-local

Public UK calibrated transfer dataset

This repo now also includes a public calibrated microdata file:

• policyengine_uk_data/storage/enhanced_cps_2025.h5
• source manifest: policyengine_uk_data/storage/enhanced_cps_source_2025.csv

The public UK calibrated transfer dataset starts from a public export of eligible households from PolicyEngine-US Enhanced CPS. In the current build that source manifest contains 28,532 households, not 1,000. The pipeline maps those records into a UKSingleYearDataset, aligns core UK-facing inputs such as council tax bands, vehicle ownership, pensions, disability/PIP, consumption, and capital gains, and then recalibrates the household weights against the UK national/region/country target registry used by the loss pipeline.

The checked-in 2025 artifact uses a pinned 0.759 USD-to-GBP conversion rate from the IRS 2025 yearly average exchange-rate table. The builder intentionally does not call a live foreign-exchange API, because the committed H5 should be reproducible from versioned code and source data. Pass exchange_rate=... to create_enhanced_cps or save_enhanced_cps when rebuilding with a different conversion assumption.

The calibration step is tested against the native 2025 loss matrix and should reduce mean absolute relative error relative to the raw transfer weights. Report full-artifact loss values from a named release artifact rather than copying them into this README.

This is a public calibrated dataset, not a replacement for the FRS or enhanced FRS. It is intended as the first step in a broader cross-country public-microdata strategy.

Programmatic entrypoints:

• policyengine_uk_data.datasets.create_enhanced_cps
• policyengine_uk_data.datasets.export_enhanced_cps_source
• policyengine_uk_data.datasets.save_enhanced_cps

Backward-compatible aliases remain available:

• policyengine_uk_data.datasets.create_policybench_transfer
• policyengine_uk_data.datasets.save_policybench_transfer