Stop passing the mortgage interest inputs policyengine-us #9605 deletes

notes/data/snap_pathways_20260930.csv.meta.json

@@ -6,7 +6,7 @@
     "alt_conventions_r25.py": "0f77fdd44e758581f7e563b0f7b70c4d4359a833b08a4ac45a614c380938775e",
     "latest_alt_r02_ira_219g.py": "3e71bab1db867988544e6f87f6dda4dc7c719d51320fbbb7558cd574a0374f6e",
     "latest_alt_salt_refund_no_prior_benefit.py": "d8a314093466caf5fe0a226f1060acba2e4364c4b87befbd80639ebf41cc4a2c",
-    "latest_alt_snap_mortgage_residence.py": "00cd13886a8c3d03c4e84944d35f7e8a1448af26838e8bc0761b914b887c70cd",
+    "latest_alt_snap_mortgage_residence.py": "5e701f8fa1b31bfeed882a0bc5160faa4ee1d2b5a67974f9d9dc60e6f6638053",
     "latest_alt_unlisted_hours_40.py": "5e6538a903112243ad85051ccba26b6133bdfbd5b9e5ba3dfa81ba690c061b32",
     "latest_c_ca_hold_2025.py": "f19a47b9583032a0602a31e52f995eee824a427a76e87a9d4257d6682a016fa2",
     "latest_c_id_hold_2025.py": "39fb99292691600cd273a1c6ef3c90847453e21e4d7b872603bcaac71727f8a5",
@@ -484,6 +484,6 @@
       }
     }
   },
-  "generated_at_utc": "2026-10-05T12:54:30.665476+00:00",
+  "generated_at_utc": "2026-10-09T12:23:57.014680+00:00",
   "script": "scripts/snap_pathways_20260930.py"
 }

policybench/scenarios.py

@@ -152,6 +152,35 @@
 # also the prompt's rule for unlisted numbers (0).
 PE_INPUT_ALIASES = {"hours_worked_last_week": "weekly_hours_worked_before_lsr"}
 
+# Manifest inputs policyengine-us has renamed. The manifests keep the name the
+# prompts were rendered from; the situation passes the value under the engine's
+# name. policyengine-us 1.728.0 renamed partnership_se_income. Every reference
+# build since then has applied the rename outside this builder: v1.1 in a
+# patched manifest, later builds in the RENAME map of
+# reference_audit/*/scripts/sweep.py.
+PE_INPUT_RENAMES = {
+    "partnership_se_income": "partnership_self_employment_net_earnings",
+}
+
+# Manifest inputs the situation leaves out, by entity. policyengine-us #9605
+# deletes the tax-unit first_home_mortgage_interest and
+# second_home_mortgage_interest inputs. Every household that lists them also
+# lists the same interest as the person-level home_mortgage_interest (on the
+# two that list a second home, the person value is the sum of both loans).
+# From 1.782.1, home_mortgage_interest_tax_unit falls back to the person-level
+# input when the tax-unit inputs are absent (from 1.804.1, #9276, it prefers
+# it), so leaving them out moves no reference on those engines. 1.620.0 through
+# 1.782.0 take the interest only from the tax-unit inputs (on 1.755.4 five
+# outputs move without them), so references built on those engines reproduce
+# from a commit before this change. The prompts still list the inputs. The
+# per-loan balances and origination years stay, since the acquisition-debt cap
+# reads them.
+PE_DROPPED_INPUTS = {
+    "tax_unit": frozenset(
+        {"first_home_mortgage_interest", "second_home_mortgage_interest"}
+    ),
+}
+
 EXCLUDED_INPUT_PREFIXES = (
     "takes_up_",
     "would_",
@@ -470,6 +499,22 @@ def num_children(self) -> int:
     def _yearize(self, value: Any) -> dict[str, Any]:
         return {str(self.year): value}
 
+    def _pe_inputs(self, entity: str, inputs: dict[str, Any]) -> dict[str, Any]:
+        """An entity's manifest inputs, yearized, under the engine's names."""
+        dropped = PE_DROPPED_INPUTS.get(entity, frozenset())
+        data: dict[str, Any] = {}
+        for key, value in inputs.items():
+            if key in dropped:
+                continue
+            name = PE_INPUT_RENAMES.get(key, key)
+            if name in data:
+                raise ValueError(
+                    f"Scenario {self.id} sets {name} twice on one {entity}: "
+                    f"directly and through the input it renames."
+                )
+            data[name] = self._yearize(value)
+        return data
+
     def to_pe_household(self) -> dict:
         """Convert to PolicyEngine-US household JSON format."""
         if self.country != "us":
@@ -483,8 +528,7 @@ def to_pe_household(self) -> dict:
                 "age": self._yearize(person.age),
                 "employment_income": self._yearize(person.employment_income),
             }
-            for key, value in person.inputs.items():
-                person_data[key] = self._yearize(value)
+            person_data.update(self._pe_inputs("person", person.inputs))
             for source, target in PE_INPUT_ALIASES.items():
                 if source in person.inputs and target not in person.inputs:
                     person_data[target] = self._yearize(person.inputs[source])
@@ -498,8 +542,7 @@ def to_pe_household(self) -> dict:
                 "age": self._yearize(person.age),
                 "employment_income": self._yearize(person.employment_income),
             }
-            for key, value in person.inputs.items():
-                person_data[key] = self._yearize(value)
+            person_data.update(self._pe_inputs("person", person.inputs))
             for source, target in PE_INPUT_ALIASES.items():
                 if source in person.inputs and target not in person.inputs:
                     person_data[target] = self._yearize(person.inputs[source])
@@ -513,23 +556,20 @@ def to_pe_household(self) -> dict:
         tax_unit_data = {
             "members": all_names,
         }
-        for key, value in self.tax_unit_inputs.items():
-            tax_unit_data[key] = self._yearize(value)
+        tax_unit_data.update(self._pe_inputs("tax_unit", self.tax_unit_inputs))
         for key, value in DEFAULT_TAKEUP_INPUTS["tax_unit"].items():
             tax_unit_data.setdefault(key, self._yearize(value))
 
         spm_unit_data = {"members": all_names}
-        for key, value in self.spm_unit_inputs.items():
-            spm_unit_data[key] = self._yearize(value)
+        spm_unit_data.update(self._pe_inputs("spm_unit", self.spm_unit_inputs))
         for key, value in DEFAULT_TAKEUP_INPUTS["spm_unit"].items():
             spm_unit_data.setdefault(key, self._yearize(value))
 
         household_data = {
             "members": all_names,
             "state_code": self._yearize(self.state),
         }
-        for key, value in self.household_inputs.items():
-            household_data[key] = self._yearize(value)
+        household_data.update(self._pe_inputs("household", self.household_inputs))
         for key, value in DEFAULT_TAKEUP_INPUTS["household"].items():
             household_data.setdefault(key, self._yearize(value))
 

reference_audit/2026-09-22/README.md

@@ -38,6 +38,8 @@ This directory records how the September 22 references and exclusion record were
   - this package's builder, `package_audit.py`.
 
   They run against the local results tree and a policyengine-us 1.755.4 environment; their paths are the ones used on 2026-09-22 and 2026-09-23.
+
+  They reproduce these records only with policybench at a commit before 2026-10-09 (origin/main 9ce4ade8 or earlier). On 2026-10-09 policybench's situation builder (`Scenario.to_pe_household`) stopped passing the tax-unit `first_home_mortgage_interest` and `second_home_mortgage_interest` inputs, which policyengine-us #9605 deletes. policyengine-us 1.755.4 takes mortgage interest only from those inputs, so with the current builder the unmodified harness moves five of the 1,984 references on 1.755.4: scenario_078 federal and state income tax, and scenario_081, scenario_088 and scenario_120 federal income tax.
 - `verification/` holds the independent reports:
   - `v1`–`v4`: GPT-6 Astra lanes re-derived each first-pass fix from primary sources and reran its sweep.
   - `v5a`, `v5b`: sourced every projected parameter behind a moved output.

reference_audit/2026-09-22/fixes/r15_snap_mortgage_interest_v2.py

@@ -1,12 +1,27 @@
-"""r15 v2: alternate SNAP shelter reading, with tax-unit-local input fallback.
+"""r15 v2: alternate SNAP shelter reading of listed mortgage interest.
 
 Classification: unlisted_input, not a proved engine-law defect. The benchmark
 prompts list mortgage interest but do not explicitly state that the encumbered
 home is the SNAP household's occupied shelter. This module implements the
-alternative reading that first-home interest (or person interest where the
-tax unit has no populated interest structure) belongs to the occupied home.
+alternative reading that the listed home mortgage interest (the person-level
+home_mortgage_interest input) belongs to the occupied home.
 It does not establish that reading as the unique interpretation of the prompt.
 
+Revised 2026-10-09. The module first read the tax-unit
+first_home_mortgage_interest and second_home_mortgage_interest inputs and, for
+a tax unit that listed them, counted first-home interest only. policyengine-us
+#9605 deletes those inputs, so it now reads only home_mortgage_interest, which
+every benchmark household that lists the tax-unit inputs also lists, with the
+same total. The two readings differ only where a second home is listed:
+scenario_046 and scenario_120, whose person-level total includes the second
+loan's 1,358.97 and 768.28. On policyengine-us 1.755.4 the sweep of all 1,984
+outputs is byte-identical under both readings and equal to this module's
+recorded sweep (triage/sweep/out/r15_snap_mortgage_interest_v2.csv, sha256
+63c9120f...),
+with situations built as before policybench stopped passing the tax-unit
+inputs. 1.755.4 takes the interest amount only from those inputs, so the
+current builder cannot reproduce that sweep on 1.755.4.
+
 7 CFR 273.9(d)(6)(ii)(A) allows continuing mortgage charges, including interest,
 for occupied shelter. Paragraph (D) also permits certain temporarily vacant
 homes; first/second-home labels alone do not resolve those occupancy facts.
@@ -18,19 +33,17 @@
 As in v1, the listed interest is a lower bound of total payments; unlisted
 principal is not invented. The SNAP-only increment is max(interest minus
 mortgage_payments, 0), preventing double counting of the reported payment.
-The first-versus-person fallback now occurs per tax unit before SPM-unit
-aggregation. The remainder of the original SNAP shelter formula is unchanged.
-No statutory dollar parameter is introduced. All 100 bundle scenarios have
-one tax unit, so this correction should leave the benchmark sweep unchanged.
+The remainder of the original SNAP shelter formula is unchanged.
+No statutory dollar parameter is introduced.
 """
 
 from policyengine_core.reforms import Reform
 from policyengine_us.model_api import *
 
 FIX_ID = "r15_snap_mortgage_interest_v2"
 DESCRIPTION = (
-    "Alternative occupied-home reading of listed mortgage interest for SNAP; "
-    "choose first-home versus person inputs per tax unit before aggregation."
+    "Alternative occupied-home reading of listed mortgage interest for SNAP, "
+    "from the person-level home_mortgage_interest input."
 )
 
 
@@ -45,19 +58,7 @@ class snap_mortgage_interest_shelter_cost(Variable):
     )
 
     def formula(spm_unit, period, parameters):
-        person = spm_unit.members
-        head = person("is_tax_unit_head", period)
-        first = person.tax_unit("first_home_mortgage_interest", period)
-        second = person.tax_unit("second_home_mortgage_interest", period)
-        # Choose the input representation separately for each tax unit.
-        # A populated structure for one tax unit must not suppress another
-        # tax unit's person-only mortgage interest within the same SPM unit.
-        interest_by_person = where(
-            first + second > 0,
-            head * first,
-            person("home_mortgage_interest", period),
-        )
-        occupied_home_interest = spm_unit.sum(interest_by_person)
+        occupied_home_interest = add(spm_unit, period, ["home_mortgage_interest"])
         mortgage_payments = spm_unit("mortgage_payments", period)
         return max_(occupied_home_interest - mortgage_payments, 0)
 

reference_audit/2026-09-28/fixes/latest_alt_snap_mortgage_residence.py

@@ -12,7 +12,16 @@
 "Continuing charges for the shelter occupied by the household, ... including mortgage
 payments ... and interest on such payments"). Unlisted principal is not invented; only
 max(interest - mortgage_payments, 0) is added, so a reported payment is never counted
-twice. First-home versus person interest is chosen per tax unit, as in r15 v2.
+twice. The interest is the person-level home_mortgage_interest input, as in r15 v2.
+
+Revised 2026-10-09, with r15 v2. The module first counted first-home interest for a tax
+unit that listed the tax-unit first/second home interest inputs; policyengine-us #9605
+deletes them, and every benchmark household that lists them lists the same total as
+home_mortgage_interest. The readings differ only where a second home is listed
+(scenario_046 and scenario_120), and no output moves: on 2.15.17 the revised module
+reproduces this sweep's recorded CSV byte for byte (verification/rerun_sweeps.json,
+csv_sha256 3dea0be8..., from the scenario builder and board of 2026-09-28), as does the
+original, and the two give byte-identical sweeps with today's builder too.
 
 Port to 2.15.17. 2.15.17's snap_excess_shelter_expense_deduction differs from 1.755.4 in
 two places (diff of the installed files): actual housing costs are multiplied by
@@ -61,16 +70,7 @@ class snap_mortgage_interest_shelter_cost(Variable):
     )
 
     def formula(spm_unit, period, parameters):
-        person = spm_unit.members
-        head = person("is_tax_unit_head", period)
-        first = person.tax_unit("first_home_mortgage_interest", period)
-        second = person.tax_unit("second_home_mortgage_interest", period)
-        interest_by_person = where(
-            first + second > 0,
-            head * first,
-            person("home_mortgage_interest", period),
-        )
-        occupied_home_interest = spm_unit.sum(interest_by_person)
+        occupied_home_interest = add(spm_unit, period, ["home_mortgage_interest"])
         mortgage_payments = spm_unit("mortgage_payments", period)
         return max_(occupied_home_interest - mortgage_payments, 0)
 

reference_audit/2026-09-28/verification/rerun_sweeps.json

@@ -170,7 +170,7 @@
       "september_22_root_cause": "r15_snap_mortgage_interest",
       "baseline": "latest_conventions",
       "csv_sha256": "3dea0be87a30b52d8e693fe8bf45fd2339979ec2f340ac342ee7f416eb7114ac",
-      "module_sha256": "00cd13886a8c3d03c4e84944d35f7e8a1448af26838e8bc0761b914b887c70cd",
+      "module_sha256": "5e701f8fa1b31bfeed882a0bc5160faa4ee1d2b5a67974f9d9dc60e6f6638053",
       "outputs": 1984,
       "moves": [
         {

scripts/snap_pathways.py

@@ -1,4 +1,12 @@
-"""Recompute SNAP eligibility pathways for the frozen 100-household snapshot."""
+"""Recompute SNAP eligibility pathways for the frozen 100-household snapshot.
+
+The committed output (notes/data/snap_pathways_20260901.csv) was built on
+policyengine-us 1.723.0. Reproduce it with policybench at a commit before
+2026-10-09. Since then the situation builder passes partnership_se_income as
+partnership_self_employment_net_earnings, which policyengine-us 1.728.0 added,
+and leaves out the tax-unit mortgage interest inputs; engines before 1.782.1
+have no person-level fallback for them.
+"""
 
 from __future__ import annotations