Add Census SPM work expense formulas

changelog_entry.yaml

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+- bump: patch
+  changes:
+    added:
+    - Add Census SPM weekly work-expense parameters and formulas for work and childcare expense caps.
+  date: 2026-04-09 00:00:00

policyengine_us/parameters/gov/census/index.yaml

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+metadata:
+  propagate_metadata_to_children: true
+  economy: false
+  household: false

policyengine_us/parameters/gov/census/spm/index.yaml

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+metadata:
+  propagate_metadata_to_children: true
+  economy: false
+  household: false

policyengine_us/parameters/gov/census/spm/work_expense/index.yaml

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+metadata:
+  propagate_metadata_to_children: true
+  economy: false
+  household: false

policyengine_us/parameters/gov/census/spm/work_expense/weekly_amount.yaml

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+description: Weekly work-expense deduction amount used in Census Supplemental Poverty Measure calculations.
+values:
+  2009-01-01: 28.0500
+  2010-01-01: 25.5000
+  2011-01-01: 27.1575
+  2012-01-01: 33.0225
+  2013-01-01: 39.3975
+  2014-01-01: 39.2530
+  2015-01-01: 40.0945
+  2016-01-01: 38.4710
+  2017-01-01: 36.3460
+  2018-01-01: 37.1025
+  2019-01-01: 39.7205
+  2020-01-01: 39.6100
+  2021-01-01: 38.0630
+  2022-01-01: 31.0080
+  2023-01-01: 33.4050
+  2024-01-01: 34.9945
+
+metadata:
+  unit: currency-USD
+  period: year
+  uprating: gov.bls.cpi.cpi_u
+  label: Census SPM weekly work-expense deduction amount
+  reference:
+    - title: Supplemental Poverty Measure (SPM) Technical Documentation
+      href: https://www2.census.gov/programs-surveys/supplemental-poverty-measure/technical-documentation/spm_techdoc.pdf
+    - title: Poverty in the United States 2023
+      href: https://www2.census.gov/library/publications/2024/demo/p60-283.pdf
+    - title: Poverty in the United States 2024
+      href: https://www2.census.gov/library/publications/2025/demo/p60-287.pdf

policyengine_us/tests/policy/baseline/household/expense/childcare/spm_unit_capped_work_childcare_expenses.yaml

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+- name: Combined work and childcare expenses are capped at the lower earner
+  period: 2024
+  absolute_error_margin: 0.001
+  input:
+    people:
+      head:
+        age: 35
+        weeks_worked: 10
+        employment_income: 40_000
+        is_household_head: true
+        is_tax_unit_head: true
+      spouse:
+        age: 33
+        weeks_worked: 20
+        employment_income: 2_000
+        is_tax_unit_spouse: true
+      child:
+        age: 8
+    tax_units:
+      tax_unit:
+        members: [head, spouse, child]
+    spm_units:
+      spm_unit:
+        members: [head, spouse, child]
+        spm_unit_pre_subsidy_childcare_expenses: 2_000
+  output:
+    spm_unit_capped_work_childcare_expenses: 2_000
+
+- name: Work expenses are preserved when they already exceed the earnings cap
+  period: 2024
+  absolute_error_margin: 0.001
+  input:
+    people:
+      head:
+        age: 41
+        weeks_worked: 52
+        employment_income: 1_500
+        is_household_head: true
+        is_tax_unit_head: true
+      child:
+        age: 5
+    tax_units:
+      tax_unit:
+        members: [head, child]
+    spm_units:
+      spm_unit:
+        members: [head, child]
+        spm_unit_pre_subsidy_childcare_expenses: 3_000
+  output:
+    spm_unit_capped_work_childcare_expenses: 1_819.714
+
+- name: Childcare is capped by the remaining lower-earner earnings after work expenses
+  period: 2024
+  absolute_error_margin: 0.001
+  input:
+    people:
+      head:
+        age: 46
+        weeks_worked: 52
+        employment_income: 9_098.57
+        is_household_head: true
+        is_tax_unit_head: true
+      spouse:
+        age: 46
+        weeks_worked: 52
+        employment_income: 30_000
+        is_tax_unit_spouse: true
+    tax_units:
+      tax_unit:
+        members: [head, spouse]
+    spm_units:
+      spm_unit:
+        members: [head, spouse]
+        spm_unit_pre_subsidy_childcare_expenses: 21_580
+  output:
+    spm_unit_capped_work_childcare_expenses: 9_098.57
+
+- name: Unmarried partner counts toward the reference person's remaining childcare cap
+  period: 2024
+  absolute_error_margin: 0.001
+  input:
+    people:
+      head:
+        age: 35
+        weeks_worked: 10
+        employment_income: 40_000
+        is_household_head: true
+        is_tax_unit_head: true
+      partner:
+        age: 33
+        weeks_worked: 20
+        employment_income: 2_000
+        is_unmarried_partner_of_household_head: true
+        is_tax_unit_head: true
+      child:
+        age: 8
+    tax_units:
+      reference_unit:
+        members: [head, child]
+      partner_unit:
+        members: [partner]
+    spm_units:
+      spm_unit:
+        members: [head, partner, child]
+        spm_unit_pre_subsidy_childcare_expenses: 2_000
+  output:
+    spm_unit_capped_work_childcare_expenses: 2_000

policyengine_us/tests/policy/baseline/household/expense/childcare/spm_unit_head_spouse_earned_cap.yaml

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+- name: Household head and spouse determine the SPM childcare earnings cap
+  period: 2024
+  absolute_error_margin: 0.001
+  input:
+    people:
+      reference_person:
+        age: 35
+        employment_income: 40_000
+        is_household_head: true
+        is_tax_unit_spouse: true
+      spouse:
+        age: 45
+        employment_income: 8_000
+        is_tax_unit_head: true
+      child:
+        age: 8
+    tax_units:
+      tax_unit:
+        members: [reference_person, spouse, child]
+    spm_units:
+      spm_unit:
+        members: [reference_person, spouse, child]
+  output:
+    spm_unit_head_spouse_earned_cap: 8_000
+
+- name: Household head and unmarried partner determine the SPM childcare earnings cap
+  period: 2024
+  absolute_error_margin: 0.001
+  input:
+    people:
+      reference_person:
+        age: 35
+        employment_income: 40_000
+        is_household_head: true
+        is_tax_unit_head: true
+      partner:
+        age: 33
+        employment_income: 2_500
+        is_unmarried_partner_of_household_head: true
+        is_tax_unit_head: true
+      child:
+        age: 8
+    tax_units:
+      reference_unit:
+        members: [reference_person, child]
+      partner_unit:
+        members: [partner]
+    spm_units:
+      spm_unit:
+        members: [reference_person, partner, child]
+  output:
+    spm_unit_head_spouse_earned_cap: 2_500
+
+- name: Farm income counts toward the Census SPM childcare earnings cap
+  period: 2024
+  absolute_error_margin: 0.001
+  input:
+    people:
+      reference_person:
+        age: 35
+        employment_income: 40_000
+        is_household_head: true
+        is_tax_unit_head: true
+      spouse:
+        age: 33
+        farm_income: 3_000
+        is_tax_unit_spouse: true
+      child:
+        age: 8
+    tax_units:
+      tax_unit:
+        members: [reference_person, spouse, child]
+    spm_units:
+      spm_unit:
+        members: [reference_person, spouse, child]
+  output:
+    spm_unit_head_spouse_earned_cap: 3_000
+
+- name: Extra adults in the SPM unit do not expand the reference person's childcare cap
+  period: 2024
+  absolute_error_margin: 0.001
+  input:
+    people:
+      reference_person:
+        age: 35
+        employment_income: 40_000
+        is_household_head: true
+        is_tax_unit_head: true
+      partner:
+        age: 33
+        employment_income: 5_000
+        is_unmarried_partner_of_household_head: true
+        is_tax_unit_head: true
+      unrelated_adult:
+        age: 55
+        employment_income: 1_000
+        is_tax_unit_head: true
+      child:
+        age: 8
+    tax_units:
+      reference_unit:
+        members: [reference_person, child]
+      partner_unit:
+        members: [partner]
+      unrelated_unit:
+        members: [unrelated_adult]
+    spm_units:
+      spm_unit:
+        members: [reference_person, partner, unrelated_adult, child]
+  output:
+    spm_unit_head_spouse_earned_cap: 5_000
+
+- name: Spouse takes precedence over unmarried partner in the reference person's childcare cap
+  period: 2024
+  absolute_error_margin: 0.001
+  input:
+    people:
+      reference_person:
+        age: 35
+        employment_income: 40_000
+        is_household_head: true
+        is_tax_unit_head: true
+      spouse:
+        age: 33
+        employment_income: 6_000
+        is_tax_unit_spouse: true
+      partner:
+        age: 31
+        employment_income: 2_500
+        is_unmarried_partner_of_household_head: true
+        is_tax_unit_head: true
+    tax_units:
+      reference_unit:
+        members: [reference_person, spouse]
+      partner_unit:
+        members: [partner]
+    spm_units:
+      spm_unit:
+        members: [reference_person, spouse, partner]
+  output:
+    spm_unit_head_spouse_earned_cap: 6_000
+
+- name: The childcare cap falls back to tax-unit head/spouse when no reference person is provided
+  period: 2024
+  absolute_error_margin: 0.001
+  input:
+    people:
+      head:
+        age: 35
+        employment_income: 40_000
+        is_tax_unit_head: true
+      spouse:
+        age: 33
+        employment_income: 4_000
+        is_tax_unit_spouse: true
+    tax_units:
+      tax_unit:
+        members: [head, spouse]
+    spm_units:
+      spm_unit:
+        members: [head, spouse]
+  output:
+    spm_unit_head_spouse_earned_cap: 4_000

policyengine_us/tests/policy/baseline/household/expense/childcare/spm_unit_work_expenses.yaml

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+- name: Work expenses apply only to adult earners in the SPM unit
+  period: 2024
+  absolute_error_margin: 0.001
+  input:
+    people:
+      adult_worker:
+        age: 40
+        weeks_worked: 10
+        employment_income: 20_000
+      adult_nonworker:
+        age: 38
+        weeks_worked: 30
+        employment_income: 0
+      child:
+        age: 12
+        weeks_worked: 52
+        employment_income: 500
+    spm_units:
+      spm_unit:
+        members: [adult_worker, adult_nonworker, child]
+  output:
+    spm_unit_work_expenses: 349.945
+
+- name: Farm-income-only adults still incur Census SPM work expenses
+  period: 2024
+  absolute_error_margin: 0.001
+  input:
+    people:
+      adult_farmer:
+        age: 40
+        weeks_worked: 10
+        farm_income: 20_000
+      adult_nonworker:
+        age: 38
+        weeks_worked: 30
+        farm_income: 0
+    spm_units:
+      spm_unit:
+        members: [adult_farmer, adult_nonworker]
+  output:
+    spm_unit_work_expenses: 349.945

policyengine_us/tests/policy/baseline/household/income/person/weeks_worked.yaml

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+- name: Weeks worked is an input variable
+  period: 2024
+  input:
+    weeks_worked: 40
+  output:
+    weeks_worked: 40
+
+- name: Weeks worked carries forward when future data is missing
+  period: 2025
+  input:
+    people:
+      person:
+        weeks_worked:
+          2024: 37
+  output:
+    weeks_worked: 37

policyengine_us/tools/default_uprating.py

@@ -60,7 +60,6 @@
     "spm_unit_spm_threshold",
     "non_sch_d_capital_gains",
     "spm_unit_state_tax_reported",
-    "spm_unit_capped_work_childcare_expenses",
     "farm_income",
     "taxable_403b_distributions",
     "qualified_tuition_expenses",