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Export parent_1_id / parent_2_id from CPS PEPAR1 / PEPAR2 #1185
Description
What happens
policyengine-us can link a child to their parents through parent_1_id and parent_2_id. SSI parental resource deeming uses these links (20 CFR 416.1202(b), PolicyEngine/policyengine-us#10040), and so does the Medicaid parent logic. The certified default (populace-us-2024-spm-20260915) carries the raw CPS parent line numbers, PEPAR1 and PEPAR2, but not the normalized ids.
Without them, microsimulations fall back to a tax-unit proxy over is_parent. That proxy:
- cannot tell a grandparent or another adult marked as a parent from the child's own parent;
- misses a co-resident parent who files in a different tax unit.
Suggested fix
Map PEPAR1 and PEPAR2 (person line numbers within the CPS household) to the frame's person_ids, and export them as parent_1_id and parent_2_id. Leave them unset when the parent is not in the household.
Support rows that clone a CPS person need the ids remapped to the clone's household.
Acceptance
- Every non-missing
PEPARmaps to a co-resident person. - The linked parent's age is plausible.
has_parent_idsholds for the children who have a CPS parent link.
Activity
PavelMakarchuk commentedon Oct 16, 2026
Another consumer of these ids: Medicaid non-filer households. PolicyEngine/policyengine-us#9406 (merged 2026-10-07, fixes policyengine-us#9404) builds the 42 CFR 435.603(f)(3) household from
parent_1_id/parent_2_id. When the ids are 0, it falls back to the family-wideis_parentproxy, so a co-resident grandparent counts as a child's second parent. The child then takes on the grandparent's income and can lose coverage, or a non-filer couple counts grandchildren in its household size.In the PolicyEngine–PRD comparison (enhanced CPS, 2025, aligned view) this is the second-largest PolicyEngine-side gap: $659K of the Medicaid difference across 158 tax units (cause
medicaid.pe_family_household). The dataset the comparison runs has no parent ids, so #9406 does not change these units yet. A certified dataset that carries the ids, mapped as described above, would close it.