Change hours_worked label to 'Hours worked per week'

[vahid-ahmadi]

Summary

• Updates the hours_worked variable label from "Total amount of hours worked by this person" to "Hours worked per week"
• The variable represents weekly hours (divided by WEEKS_IN_YEAR for weekly_hours, multiplied by 52 for annual wage calculations)

Fixes #451

Test plan

• Verify label appears correctly in the PolicyEngine app

🤖 Generated with Claude Code

[MaxGhenis]

The proposed label "Hours worked per week" contradicts how hours_worked is defined in the model:

• policyengine-uk-data/policyengine_uk_data/datasets/frs.py:129 builds the input as hours_worked = tothours * 52 — i.e. FRS weekly hours scaled up to an annual figure.
• policyengine_uk/variables/household/income/weekly_hours.py defines weekly_hours = hours_worked / WEEKS_IN_YEAR, which only makes sense if hours_worked is annual.

So hours_worked is an annual hours variable. Changing the label to "Hours worked per week" would cause model users to interpret e.g. 2,000 as weekly hours instead of ~40 weekly / ~2,000 annual — the kind of off-by-52 bug that's painful to spot after the fact.

If the intent is to make it friendlier, the accurate replacement is something like "Annual hours worked". If you'd rather change the semantics to weekly, that's a much bigger change — we'd also need to update frs.py to drop the * 52, update weekly_hours.py, and find any downstream callers that divide/multiply by WEEKS_IN_YEAR.

Flagging as blocking until one of those is chosen. Happy to push a one-line change to "Annual hours worked" if that's what you want.

[vahid-ahmadi]

Good catch — you're right, hours_worked is annual. Verified:

• policyengine-uk-data/.../frs.py builds it as tothours * 52
• variables/household/income/weekly_hours.py:16 derives weekly as hours_worked / WEEKS_IN_YEAR
• dynamics/labour_supply.py:286 computes hours_per_week = hours_worked / 52
• Test values (e.g. 1500, 1800, 2200) are annual-scale

Pushed 3d82a25c changing the label to "Annual hours worked" and updated the changelog entry to match. Keeping semantics as-is — not switching to weekly.

[MaxGhenis]

Verified against the formula: weekly_hours = hours_worked / WEEKS_IN_YEAR, so hours_worked is annual. The updated label "Annual hours worked" matches. The PR title/body still say "per week" — that was an earlier draft; the actual diff is correct. Approving.