Exclude students from the SNAP unit with certain exceptions.

changelog_entry.yaml

@@ -0,0 +1,4 @@
+- bump: minor
+  changes:
+    added:
+    - Exclude students from the SNAP unit with certain exceptions. 

policyengine_us/parameters/gov/usda/snap/max_allotment.yaml

@@ -7,6 +7,8 @@ main:
       - range(1, 9)
     label: SNAP max allotment
   CONTIGUOUS_US:
+    0:
+      2020-10-01: 0
     1:
       2020-10-01: 204
       2021-01-01: 234
@@ -64,6 +66,8 @@ main:
       2023-10-01: 1_751
       2024-10-01: 1_756
   AK_URBAN:
+    0:
+      2020-10-01: 0
     1:
       2020-10-01: 251
       2021-01-01: 289
@@ -121,6 +125,8 @@ main:
       2023-10-01: 2_246
       2024-10-01: 2_265
   AK_RURAL_1:
+    0:
+      2020-10-01: 0
     1:
       2020-10-01: 320
       2021-01-01: 368
@@ -178,6 +184,8 @@ main:
       2023-10-01: 2_865
       2024-10-01: 2_888
   AK_RURAL_2:
+    0:
+      2020-10-01: 0
     1:
       2020-10-01: 390
       2021-01-01: 448
@@ -235,6 +243,8 @@ main:
       2023-10-01: 3_487
       2024-10-01: 3_516
   GU:
+    0:
+      2020-10-01: 0
     1:
       2020-10-01: 300
       2021-01-01: 345
@@ -292,6 +302,8 @@ main:
       2023-10-01: 2_581
       2024-10-01: 2_588
   HI:
+    0:
+      2020-10-01: 0
     1:
       2020-10-01: 375
       2021-01-01: 432
@@ -349,6 +361,8 @@ main:
       2023-10-01: 3_166
       2024-10-01: 3_102
   VI:
+    0:
+      2020-10-01: 0
     1:
       2020-10-01: 262
       2021-01-01: 301

policyengine_us/parameters/gov/usda/snap/student/age_threshold.yaml

@@ -0,0 +1,23 @@
+description: The United States includes students in the Supplemental Nutrition Assistance Program unit if their age falls into the following range.
+brackets:
+  - threshold:
+      2018-01-01: 0
+    amount:
+      2018-01-01: true 
+  - threshold:
+      2018-01-01: 18
+    amount:
+      2018-01-01: false 
+  - threshold:
+      2018-01-01: 50
+    amount:
+      2018-01-01: true
+
+metadata:
+  type: single_amount
+  threshold_unit: year
+  amount_unit: bool
+  label: SNAP student age eligibility threshold
+  reference:
+    - title: 7 U.S. Code § 2015 - Eligibility disqualifications (e)(1)
+      href: https://www.law.cornell.edu/uscode/text/7/2015

policyengine_us/parameters/gov/usda/snap/student/working_hours_threshold.yaml

@@ -0,0 +1,12 @@
+description: The United States includes students who work more than this number of weekly hours in the Supplemental Nutrition Assistance Program unit.
+
+values:
+  2005-01-01: 20
+
+metadata:
+  unit: hours
+  label: SNAP student working hours threshold
+  period: week
+  reference:
+    - title: 7 U.S. Code § 2015 - Eligibility disqualifications (e)(4)
+      href: https://www.law.cornell.edu/uscode/text/7/2015

policyengine_us/tests/policy/baseline/gov/usda/snap/eligibility/is_snap_eligible.yaml

@@ -27,3 +27,75 @@
     meets_snap_categorical_eligibility: false
   output:
     is_snap_eligible: true
+
+- name: One ineligible student present
+  period: 2022
+  input:
+    people:
+      person1:
+        is_snap_ineligible_student: false
+      person2:
+        is_snap_ineligible_student: false
+      person3:
+        is_snap_ineligible_student: true
+    spm_units:
+      spm_unit1:
+        members: [person1, person2, person3]
+        meets_snap_gross_income_test: true
+        meets_snap_net_income_test: true
+        meets_snap_asset_test: true
+        meets_snap_categorical_eligibility: false
+  output:
+    is_snap_eligible: true
+
+- name: Every person ineligible
+  period: 2022
+  input:
+    people:
+      person1:
+        is_snap_ineligible_student: true
+      person2:
+        is_snap_ineligible_student: true
+      person3:
+        is_snap_ineligible_student: true
+    spm_units:
+      spm_unit1:
+        members: [person1, person2, person3]
+        meets_snap_gross_income_test: true
+        meets_snap_net_income_test: true
+        meets_snap_asset_test: true
+        meets_snap_categorical_eligibility: false
+  output:
+    is_snap_eligible: false
+
+- name: Single ineligible student
+  period: 2022
+  input:
+    people:
+      person1:
+        is_snap_ineligible_student: true
+    spm_units:
+      spm_unit1:
+        members: [person1]
+        meets_snap_gross_income_test: true
+        meets_snap_net_income_test: true
+        meets_snap_asset_test: true
+        meets_snap_categorical_eligibility: false
+  output:
+    is_snap_eligible: false
+
+- name: Single eligible person
+  period: 2022
+  input:
+    people:
+      person1:
+        is_snap_ineligible_student: false
+    spm_units:
+      spm_unit1:
+        members: [person1]
+        meets_snap_gross_income_test: true
+        meets_snap_net_income_test: true
+        meets_snap_asset_test: true
+        meets_snap_categorical_eligibility: false
+  output:
+    is_snap_eligible: true

policyengine_us/tests/policy/baseline/gov/usda/snap/eligibility/student/is_snap_ineligible_student.yaml

@@ -0,0 +1,21 @@
+- name: Student who does not meet any exemption criteria
+  period: 2022
+  input:
+    is_full_time_student: true
+    age: 18
+    is_disabled: false
+    weekly_hours_worked: false
+    is_parent: false
+  output:
+    is_snap_ineligible_student: true
+
+- name: Student who is under the age limit
+  period: 2022
+  input:
+    is_full_time_student: true
+    age: 17
+    is_disabled: false
+    weekly_hours_worked: false
+    is_parent: false
+  output:
+    is_snap_ineligible_student: false

policyengine_us/tests/policy/baseline/gov/usda/snap/snap_unit.yaml

@@ -0,0 +1,50 @@
+- name: Household with one ineligible studnet
+  period: 2022
+  input:
+    people: 
+      person1:
+        is_snap_ineligible_student: false
+      person2:
+        is_snap_ineligible_student: false
+      person3:
+        is_snap_ineligible_student: true
+    spm_units:
+      spm_unit1:
+        members: [person1, person2, person3]
+        spm_unit_size: 3
+  output:
+    snap_unit_size: 2
+
+- name: Everybody eligible
+  period: 2022
+  input:
+    people: 
+      person1:
+        is_snap_ineligible_student: false
+      person2:
+        is_snap_ineligible_student: false
+      person3:
+        is_snap_ineligible_student: false
+    spm_units:
+      spm_unit1:
+        members: [person1, person2, person3]
+        spm_unit_size: 3
+  output:
+    snap_unit_size: 3
+
+- name: No eligible people
+  period: 2022
+  input:
+    people: 
+      person1:
+        is_snap_ineligible_student: true
+      person2:
+        is_snap_ineligible_student: true
+      person3:
+        is_snap_ineligible_student: true
+    spm_units:
+      spm_unit1:
+        members: [person1, person2, person3]
+        spm_unit_size: 3
+  output:
+    snap_unit_size: 0

policyengine_us/variables/gov/usda/snap/eligibility/is_snap_eligible.py

@@ -21,4 +21,10 @@ def formula(spm_unit, period, parameters):
         categorical_eligibility = spm_unit(
             "meets_snap_categorical_eligibility", period
         )
-        return normal_eligibility | categorical_eligibility
+        person = spm_unit.members
+        eligible_person_present = spm_unit.any(
+            ~person("is_snap_ineligible_student", period)
+        )
+        return (
+            normal_eligibility | categorical_eligibility
+        ) & eligible_person_present

policyengine_us/variables/gov/usda/snap/eligibility/student/is_snap_ineligible_student.py

@@ -0,0 +1,28 @@
+from policyengine_us.model_api import *
+
+
+class is_snap_ineligible_student(Variable):
+    value_type = bool
+    entity = Person
+    label = "Is an ineligible student for SNAP"
+    documentation = "Whether this person is an ineligible student for SNAP and can not be counted towards the household size"
+    definition_period = YEAR
+    reference = "https://www.law.cornell.edu/uscode/text/7/2015"
+
+    def formula(person, period, parameters):
+        student = person(
+            "is_full_time_student", period
+        )  # part-time students should also count
+        age = person("age", period)
+        p = parameters(period).gov.usda.snap.student
+        age_eligible = p.age_threshold.calc(age)
+        disabled = person("is_disabled", period)
+        hours_worked = person("weekly_hours_worked", period)
+        hours_eligible = hours_worked >= p.working_hours_threshold
+        # The parental status applies to children under 6 (under 12
+        # if no care available)
+        # Single parents with children under 12 are also eligible
+        is_parent = person("is_parent", period)
+        return student & ~(
+            age_eligible | disabled | hours_eligible | is_parent
+        )

policyengine_us/variables/gov/usda/snap/income/deductions/snap_standard_deduction.py

@@ -15,5 +15,6 @@ def formula(spm_unit, period, parameters):
             period
         ).gov.usda.snap.income.deductions.standard
         state_group = spm_unit.household("state_group_str", period)
-        capped_household_size = min_(spm_unit("spm_unit_size", period), 6)
+        unit = spm_unit("snap_unit_size", period)
+        capped_household_size = clip(unit, 1, 6)
         return standard_deductions[state_group][capped_household_size]

policyengine_us/variables/gov/usda/snap/income/snap_fpg.py

@@ -12,7 +12,7 @@ class snap_fpg(Variable):
     definition_period = MONTH
 
     def formula(spm_unit, period, parameters):
-        n = spm_unit("spm_unit_size", period.this_year)
+        n = spm_unit("snap_unit_size", period.this_year)
         state_group = spm_unit.household("state_group_str", period.this_year)
         year = period.start.year
         month = period.start.month

policyengine_us/variables/gov/usda/snap/snap_max_allotment.py

@@ -14,11 +14,11 @@ def formula(spm_unit, period, parameters):
         MAX_HOUSEHOLD_SIZE_UNDER_MAIN = 8
         snap_region = spm_unit.household("snap_region_str", period)
         household_size = min_(
-            spm_unit("spm_unit_size", period), MAX_HOUSEHOLD_SIZE_UNDER_MAIN
+            spm_unit("snap_unit_size", period), MAX_HOUSEHOLD_SIZE_UNDER_MAIN
         )
         additional_members = max_(
             0,
-            spm_unit("spm_unit_size", period) - MAX_HOUSEHOLD_SIZE_UNDER_MAIN,
+            spm_unit("snap_unit_size", period) - MAX_HOUSEHOLD_SIZE_UNDER_MAIN,
         )
         main_allotment = max_allotments.main[snap_region][household_size]
         additional_allotment = (

policyengine_us/variables/gov/usda/snap/snap_min_allotment.py

@@ -23,7 +23,7 @@ def formula(spm_unit, period, parameters):
         ]
 
         # Minimum benefits only apply to households up to a certain size.
-        size = spm_unit("spm_unit_size", period)
+        size = spm_unit("snap_unit_size", period)
         eligible = size <= snap.min_allotment.maximum_household_size
         min_allotment = eligible * min_allotment.rate * relevant_max_allotment
 

policyengine_us/variables/gov/usda/snap/snap_unit.py

@@ -0,0 +1,15 @@
+from policyengine_us.model_api import *
+
+
+class snap_unit_size(Variable):
+    value_type = int
+    entity = SPMUnit
+    label = "SNAP unit"
+    definition_period = YEAR
+
+    def formula(spm_unit, period, parameters):
+        unit_size = spm_unit("spm_unit_size", period)
+        person = spm_unit.members
+        ineligible_student = person("is_snap_ineligible_student", period)
+        ineligible_students = spm_unit.sum(ineligible_student)
+        return max_(unit_size - ineligible_students, 0)

policyengine_us/variables/household/demographic/person/is_father.py

@@ -12,5 +12,5 @@ def formula(person, period, parameters):
         # male and has some children in their own household (provided in the
         # CPS).
         female = person("is_female", period)
-        has_children = person("own_children_in_household", period) > 0
+        has_children = person("is_parent", period)
         return ~female & has_children

policyengine_us/variables/household/demographic/person/is_mother.py

@@ -14,6 +14,6 @@ def formula(person, period, parameters):
         #    (provided in the CPS).
         # 2. Breastfeeding (user-input).
         female = person("is_female", period)
-        has_children = person("own_children_in_household", period) > 0
+        has_children = person("is_parent", period)
         breastfeeding = person("is_breastfeeding", period)
         return breastfeeding | (female & has_children)

policyengine_us/variables/household/demographic/person/is_parent.py

@@ -0,0 +1,11 @@
+from policyengine_us.model_api import *
+
+
+class is_parent(Variable):
+    value_type = bool
+    entity = Person
+    label = "Is a parent"
+    definition_period = YEAR
+
+    def formula(person, period, parameters):
+        return person("own_children_in_household", period) > 0