Imputed savings put CPS SSI reporters over the resource limit, so reforms 'add' people who already report SSI #1184

What happens

On the certified default (populace-us-2024-spm-20260915, policyengine-us 2.2.1), some people who reported SSI in the CPS have imputed savings above SSI's resource limit. The take-up stage keeps their claiming flag on, but the resource test keeps them off SSI under current law. Any reform that raises the limit then "adds" them, although they report already receiving SSI.

Here a CPS SSI reporter is a source person with SSI_VAL > 0 on any row, the take-up stage's anchor. Every such row carries takes_up_ssi_if_eligible = True.

Source: results/admin-checks/new_recipients_by_reporting.csv in PolicyEngine/ssi-asset-limits (merged in #1).

For the $10k/$20k limits, this is a sixth of the adult row that otherwise matches CBPP's 154,000.

Why

scf_wealth draws each household's liquid assets (50/50 SIPP 2023 / SCF 2022) without conditioning on SSI receipt. In the data, current SSI recipients hold almost no countable resources, because they cannot hold more than the limit.

Suggested fix (attributes only)

Use reported SSI receipt (CPS SSI_VAL > 0) as a predictor in the asset imputation. SIPP observes both receipt and assets, so reporters would draw from recipients' observed asset distribution. This conditions on an observed attribute, not on the resource limit, so it stays policy-invariant.

Acceptance

• Among CPS SSI reporters with the take-up flag, the weighted share failing current-law meets_ssi_resource_test falls to roughly SIPP's share of recipients above the limit.
• SSA age-band reconciliation does not regress.

Related: #584 (asset gradient in claiming), #1178 (Social Security erased by the PUF channel), #880 (married couples overcounted).