Skip to content

Clarify housing resource assumptions in the reproducibility appendix #5

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
MaxGhenis merged 3 commits into from
Sep 12, 2026
Merged

Clarify housing resource assumptions in the reproducibility appendix #5

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
5e883a3
Clarify SPM resource allocation and program-benefit independence
MaxGhenis Sep 12, 2026
298d97e
Pin the separately documented resource conventions
MaxGhenis Sep 12, 2026
e98e98b
Clarify the tenant-payment allocation sequence
MaxGhenis Sep 12, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
29 changes: 25 additions & 4 deletions paper/index.qmd
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@ author:
affiliations:
- name: PolicyEngine
email: max@policyengine.org
date: 2026-09-10
date: 2026-09-12
date-format: long
bibliography: ../bibliography/references.bib
format:
Expand Down Expand Up @@ -820,14 +820,35 @@ standalone calculator, with year-specific national bases, housing shares,
geographic indices, assignments, and source fingerprints. The pinned
calculator includes PolicyEngine, Microcosm, and native Axiom adapters
that consume these quantities through explicit contracts. Population
sources supply native SPM membership
and composition roles; tax-benefit models retain responsibility for
resources, and the population system retains its weights. A change of
sources supply native SPM membership and composition roles;
tax-benefit models retain responsibility for resources, including
ordinary income, program awards, and the housing-assistance cap, and the
population system retains its weights. A change of
rules engine does not require a second expenditure forecast. Runtime
parity and release integration are separate checks from the statistical
validity of the projection. The snapshot date does not reconstruct
historical information sets or certify a public deployment.

The resource conventions below are specified separately in the
[PolicyEngine-US resource contract](https://github.com/PolicyEngine/policyengine-us/blob/7b2ef566aee52db17fe1d8ab5d0a744669802506/docs/spm.md).
That contract is outside the calculator artifacts pinned above and does
not reproduce or revise the preserved historical poverty sensitivity.
In population applications, the threshold's housing portion limits the
housing subsidy counted as an SPM resource. The accompanying resource
specification sums modeled awards within a household, allocates the total
to SPM units by member share, and applies each unit's cap after allocation,
following Census's subsidy proration [@spmtechnical, p. 14]. It treats
interview-time public or reduced-rent housing status as full-year
assistance to a program family represented by the householder's SPM unit,
because the survey does not identify that family. For units whose modeled
award is positive before allocation, it allocates their tenant
contributions by the same member shares; Census
does not document this split, so it is a declared consistency assumption
rather than verified production parity. Program eligibility and awards
do not depend on the cap. These choices concern resource valuation and
do not change the threshold estimates reported here. They do not revise
the separately preserved historical poverty sensitivity.

Tables regenerate from the recorded artifacts. The build checks their
hashes before generating outputs in temporary storage and comparing the
results with the saved tables and evaluation JSON. Archived tables no
Expand Down
Loading