Stop counting a benefit unit's claimant or partner as its own child or qualifying young person

changelog.d/claimant-not-own-child-or-qyp.fixed.md

@@ -0,0 +1 @@
+- Stopped counting a benefit unit's own claimant or partner as its child or qualifying young person for Child Benefit, Child Tax Credit and Pension Credit (SSCBA 1992 ss.141 and 143 and Child Benefit (General) Regulations 2006 regs 12-13; CTC Regs 2002 reg. 3; SPC Regs 2002 Sch. IIA para. 3), so a lone 16- to 19-year-old no longer gets Child Benefit, a Child Tax Credit child element or a Pension Credit child addition for themselves.

policyengine_uk/tests/policy/baseline/finance/benefit/claimant_not_own_child_or_qualifying_young_person.yaml

@@ -0,0 +1,244 @@
+# A benefit unit's claimant or partner is never its own child or qualifying
+# young person for Child Benefit (SSCBA 1992 ss.141, 143(1); Child Benefit
+# (General) Regulations 2006 regs 12-13), Child Tax Credit (CTC Regs 2002
+# reg. 3(1) Rule 1, Cases G-H) or Pension Credit (SPC Regs 2002 Sch. IIA
+# para. 3). Rates: Child Benefit eldest child £27.05 a week in 2026-27
+# (gov/hmrc/child_benefit/amount/eldest.yaml); Pension Credit child addition
+# £69.98 and first-child addition £81.07 a week in 2026-27
+# (gov/dwp/pension_credit/guarantee_credit/child/addition.yaml,
+# .../child/first/addition.yaml); CTC child element £3,455 a year in 2024-25
+# (gov/dwp/tax_credits/child_tax_credit/elements/child_element.yaml).
+
+- name: Case 1, a lone 17-year-old at school is a qualifying young person but not their own.
+  period: 2026
+  absolute_error_margin: 0.01
+  input:
+    people:
+      young_person:
+        age: 17
+        current_education: UPPER_SECONDARY
+        is_claimant_or_partner: true
+    benunits:
+      benunit:
+        members: [young_person]
+  output:
+    is_qualifying_young_person_for_child_benefit: true
+    is_qualifying_young_person_for_pension_credit: true
+    is_child_or_qualifying_young_person_for_child_benefit: false
+    is_child_or_qualifying_young_person_for_pension_credit: false
+    child_benefit_entitlement: 0
+    child_minimum_guarantee_addition: 0
+
+- name: Case 2, a lone parent aged 17 at school gets Child Benefit and the Pension Credit child addition for the baby only.
+  period: 2026
+  absolute_error_margin: 0.01
+  input:
+    people:
+      parent:
+        age: 17
+        current_education: UPPER_SECONDARY
+        is_parent: true
+        is_claimant_or_partner: true
+      baby:
+        age: 1
+        is_claimant_or_partner: false
+    benunits:
+      benunit:
+        members: [parent, baby]
+  output:
+    is_child_or_qualifying_young_person_for_child_benefit: [false, true]
+    is_child_or_qualifying_young_person_for_pension_credit: [false, true]
+    # The baby is the only, so eldest, child: 27.05 * 52.
+    child_benefit_entitlement: 1_406.60
+    # Born after 6 April 2017, so the standard addition: 69.98 * 52.
+    child_minimum_guarantee_addition: 3_638.96
+
+- name: Case 3, no Child Benefit or Pension Credit child addition for a partner aged 18 at school.
+  period: 2026
+  absolute_error_margin: 0.01
+  input:
+    people:
+      claimant:
+        age: 30
+        is_claimant_or_partner: true
+      partner:
+        age: 18
+        current_education: UPPER_SECONDARY
+        is_claimant_or_partner: true
+    benunits:
+      benunit:
+        members: [claimant, partner]
+  output:
+    is_qualifying_young_person_for_child_benefit: [false, true]
+    is_child_or_qualifying_young_person_for_child_benefit: [false, false]
+    is_child_or_qualifying_young_person_for_pension_credit: [false, false]
+    child_benefit_entitlement: 0
+    child_minimum_guarantee_addition: 0
+
+- name: Case 4, a parent's 17-year-old at school stays the family's qualifying young person.
+  period: 2026
+  absolute_error_margin: 0.01
+  input:
+    people:
+      parent:
+        age: 40
+        is_parent: true
+        is_claimant_or_partner: true
+      young_person:
+        age: 17
+        current_education: UPPER_SECONDARY
+        is_claimant_or_partner: false
+    benunits:
+      benunit:
+        members: [parent, young_person]
+  output:
+    is_child_or_qualifying_young_person_for_child_benefit: [false, true]
+    is_child_or_qualifying_young_person_for_pension_credit: [false, true]
+    child_benefit_entitlement: 1_406.60
+    # Born before 6 April 2017 and the eldest: 81.07 * 52.
+    child_minimum_guarantee_addition: 4_215.64
+
+- name: Case 5, Child Tax Credit counts no child element for a lone 17-year-old at school.
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    people:
+      young_person:
+        age: 17
+        current_education: UPPER_SECONDARY
+        is_claimant_or_partner: true
+    benunits:
+      benunit:
+        members: [young_person]
+  output:
+    is_qualifying_young_person_for_child_tax_credit: true
+    is_child_or_qualifying_young_person_for_child_tax_credit: false
+    is_responsible_for_child_or_qualifying_young_person_for_child_tax_credit: false
+    CTC_child_element: 0
+
+- name: Case 6, Child Tax Credit counts one child element for a parent's 17-year-old at school.
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    people:
+      parent:
+        age: 40
+        is_parent: true
+        is_claimant_or_partner: true
+      young_person:
+        age: 17
+        current_education: UPPER_SECONDARY
+        is_claimant_or_partner: false
+    benunits:
+      benunit:
+        members: [parent, young_person]
+  output:
+    is_child_or_qualifying_young_person_for_child_tax_credit: [false, true]
+    is_responsible_for_child_or_qualifying_young_person_for_child_tax_credit: true
+    CTC_child_element: 3_455
+
+- name: Case 7, Child Tax Credit counts the baby but not the parent aged 17 at school.
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    people:
+      parent:
+        age: 17
+        current_education: UPPER_SECONDARY
+        is_parent: true
+        is_claimant_or_partner: true
+      baby:
+        age: 1
+        is_claimant_or_partner: false
+    benunits:
+      benunit:
+        members: [parent, baby]
+  output:
+    is_child_or_qualifying_young_person_for_child_tax_credit: [false, true]
+    CTC_child_element: 3_455
+
+- name: Case 8, Child Tax Credit counts no child element for a partner aged 18 at school (Case H).
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    people:
+      claimant:
+        age: 30
+        is_claimant_or_partner: true
+      partner:
+        age: 18
+        current_education: UPPER_SECONDARY
+        is_claimant_or_partner: true
+    benunits:
+      benunit:
+        members: [claimant, partner]
+  output:
+    is_qualifying_young_person_for_child_tax_credit: [false, true]
+    is_child_or_qualifying_young_person_for_child_tax_credit: [false, false]
+    CTC_child_element: 0
+
+# Known limitation, not a rule of law. When a household is entered with no
+# roles, is_claimant_or_partner reads an 18- or 19-year-old at school as the
+# head's partner unless the head is at least 16 years older or someone is
+# flagged a parent. The model then treats the two as a couple everywhere,
+# and so pays no Child Benefit for the 18-year-old. Supplying the roles, or
+# flagging the parent, restores it. In law the head can claim for a young
+# person who lives with them and is not their partner (SSCBA 1992
+# s.143(1)(a); Child Benefit (General) Regulations 2006 regs 12-13).
+- name: Case 9, with no roles supplied an 18-year-old at school 15 years younger than the head is read as their partner.
+  period: 2026
+  absolute_error_margin: 0.01
+  input:
+    people:
+      head:
+        age: 33
+      student:
+        age: 18
+        current_education: UPPER_SECONDARY
+    benunits:
+      benunit:
+        members: [head, student]
+  output:
+    is_claimant_or_partner: [true, true]
+    is_couple: true
+    is_child_or_qualifying_young_person_for_child_benefit: [false, false]
+    child_benefit_entitlement: 0
+
+- name: Case 10, the same family with the head flagged a parent gets Child Benefit for the 18-year-old.
+  period: 2026
+  absolute_error_margin: 0.01
+  input:
+    people:
+      head:
+        age: 33
+        is_parent: true
+      student:
+        age: 18
+        current_education: UPPER_SECONDARY
+    benunits:
+      benunit:
+        members: [head, student]
+  output:
+    is_claimant_or_partner: [true, false]
+    is_couple: false
+    is_child_or_qualifying_young_person_for_child_benefit: [false, true]
+    child_benefit_entitlement: 1_406.60
+
+- name: Case 11, the same family with the roles supplied gets Child Benefit for the 18-year-old.
+  period: 2026
+  absolute_error_margin: 0.01
+  input:
+    people:
+      head:
+        age: 33
+        is_claimant_or_partner: true
+      student:
+        age: 18
+        current_education: UPPER_SECONDARY
+        is_claimant_or_partner: false
+    benunits:
+      benunit:
+        members: [head, student]
+  output:
+    is_child_or_qualifying_young_person_for_child_benefit: [false, true]
+    child_benefit_entitlement: 1_406.60

policyengine_uk/tests/policy/baseline/finance/benefit/general.yaml

@@ -5,14 +5,16 @@
     age: 14
   output:
     is_child_or_qualifying_young_person_for_child_benefit: true
-- name: Child Benefit child or qualifying young person for student in FE
+- name: A student in FE is a Child Benefit qualifying young person, but alone is their own claimant, not their own qualifying young person
   period: 2020
   absolute_error_margin: 0
   input:
     age: 17
     current_education: POST_SECONDARY
   output:
-    is_child_or_qualifying_young_person_for_child_benefit: true
+    is_qualifying_young_person_for_child_benefit: true
+    is_claimant_or_partner: true
+    is_child_or_qualifying_young_person_for_child_benefit: false
 - name: Benefits premiums summed
   period: 2020
   absolute_error_margin: 0

policyengine_uk/tests/test_child_and_adult_definitions_properties.py

@@ -6,8 +6,10 @@
    approved training, own-benefit receipt and looked-after status, the four
    programmes' child predicates mean under 16. Their young-person predicates
    agree with the statutory age/education/entry conditions the model encodes.
-   Legacy children are Child Benefit children/QYPs other than claimants,
-   partners and children placed by a local authority; the HBAI fallback and
+   Child Benefit, Child Tax Credit and Pension Credit children/QYPs exclude
+   the benefit unit's claimant and partner, as do legacy children, which are
+   Child Benefit children/QYPs other than children placed by a local
+   authority; UC's consumers apply their own claimant filter. The HBAI fallback and
    the claimant-or-partner presumption follow their documented assumptions.
    An unflagged member at least 16 years younger than a claimant flagged as
    a parent is never their partner, at any age, unless a member under 20 and
@@ -196,12 +198,18 @@ def qualifying_young_person(p, programme):
     return True
 
 
-def child_or_young_person(p, programme):
+def child_or_young_person(p, programme, claimant=False):
     # Encoded responsibility filters, without their statutory exceptions:
     # https://www.legislation.gov.uk/uksi/2013/376/regulation/4
     # https://www.legislation.gov.uk/uksi/2002/2007/regulation/3
     # https://www.legislation.gov.uk/uksi/2002/1792/schedule/IIA
+    # No one is responsible for themselves or their partner (SSCBA s.143;
+    # CTC reg 3 Rule 1 and Cases G-H; SPC Sch IIA para 3). UC's flag keeps the
+    # claimant and its consumers filter them (UC reg 4).
+    # https://www.legislation.gov.uk/ukpga/1992/4/section/143
     eligible = statutory_child(p["age"]) or qualifying_young_person(p, programme)
+    if programme != "universal_credit" and claimant:
+        return False
     if programme != "child_benefit" and p["is_looked_after_by_local_authority"]:
         return False
     return eligible
@@ -267,10 +275,8 @@ def legacy_child_or_young_person(p, claimant):
     # anyone placed by a local authority (IS reg16(4), HB reg21(3)):
     # https://www.legislation.gov.uk/uksi/1987/1967/regulation/16
     # https://www.legislation.gov.uk/uksi/2006/213/regulation/21
-    return (
-        not claimant
-        and not p["is_looked_after_by_local_authority"]
-        and child_or_young_person(p, "child_benefit")
+    return not p["is_looked_after_by_local_authority"] and child_or_young_person(
+        p, "child_benefit", claimant
     )
 
 
@@ -310,6 +316,11 @@ def assert_definitions(families, year=YEAR):
         [non_advanced_education(p) for p in people],
         year,
     )
+    hbai = [hbai_dependent_child(p, family) for family in families for p in family]
+    assert_values(sim, "is_hbai_dependent_child", hbai, year)
+    assert_values(sim, "is_hbai_adult", [not child for child in hbai], year)
+    claimants = [c for family in families for c in claimants_or_partners(family)]
+    assert_values(sim, "is_claimant_or_partner", claimants, year)
     for programme in PROGRAMMES:
         assert_values(sim, f"is_child_for_{programme}", children, year)
         assert_values(
@@ -321,14 +332,9 @@ def assert_definitions(families, year=YEAR):
         assert_values(
             sim,
             f"is_child_or_qualifying_young_person_for_{programme}",
-            [child_or_young_person(p, programme) for p in people],
+            [child_or_young_person(p, programme, c) for p, c in zip(people, claimants)],
             year,
         )
-    hbai = [hbai_dependent_child(p, family) for family in families for p in family]
-    assert_values(sim, "is_hbai_dependent_child", hbai, year)
-    assert_values(sim, "is_hbai_adult", [not child for child in hbai], year)
-    claimants = [c for family in families for c in claimants_or_partners(family)]
-    assert_values(sim, "is_claimant_or_partner", claimants, year)
     # SSCBA s137 and IS reg14 / HB reg19, projected to the encoded family:
     # https://www.legislation.gov.uk/ukpga/1992/4/section/137
     # https://www.legislation.gov.uk/uksi/1987/1967/regulation/14