Project Scottish Child Payment and PAWHP by September CPI

changelog.d/scottish-september-cpi.fixed.md

@@ -0,0 +1 @@
+Project Scottish Child Payment and Pension Age Winter Heating Payment by the previous September's CPI with annual nearest-5p rounding, replacing outdated Scottish Child Payment forecast anchors from 2027.

policyengine_uk/parameters/gov/social_security_scotland/pawhp/amount/higher.yaml

@@ -20,4 +20,20 @@ values:
 metadata:
   unit: currency-GBP
   label: PAWHP higher (80+) amount
-  uprating: gov.economic_assumptions.indices.obr.consumer_price_index
+  # September CPI and nearest-5p rounding follow Scottish Ministers' current
+  # policy; s86A leaves the choice of relevant prices to Ministers.
+  # Apply each year's rise to the previous rounded rate each April.
+  uprating:
+    parameter: gov.benefit_uprating_cpi
+    at_defined_interval:
+      start: "0001-01-01"
+      end: "0002-01-01"
+      enactment: "0002-04-01"
+    rounding:
+      type: nearest
+      interval: 0.05
+  reference:
+    - title: Social Security (Scotland) Act 2018, section 86A (relevant prices chosen by Scottish Ministers)
+      href: https://www.legislation.gov.uk/asp/2018/9/section/86A
+    - title: Social Security Assistance in Scotland - up-rating for inflation 2026-2027, sections 2 and 3 (September CPI and nearest 5p)
+      href: https://www.gov.scot/publications/social-security-assistance-scotland-up-rating-inflation-2026-27/pages/3/

policyengine_uk/parameters/gov/social_security_scotland/pawhp/amount/higher_shared_with_80_or_over.yaml

@@ -15,4 +15,20 @@ values:
 metadata:
   unit: currency-GBP
   label: PAWHP shared amount 80 and over, living with 80 and over
-  uprating: gov.economic_assumptions.indices.obr.consumer_price_index
+  # September CPI and nearest-5p rounding follow Scottish Ministers' current
+  # policy; s86A leaves the choice of relevant prices to Ministers.
+  # Apply each year's rise to the previous rounded rate each April.
+  uprating:
+    parameter: gov.benefit_uprating_cpi
+    at_defined_interval:
+      start: "0001-01-01"
+      end: "0002-01-01"
+      enactment: "0002-04-01"
+    rounding:
+      type: nearest
+      interval: 0.05
+  reference:
+    - title: Social Security (Scotland) Act 2018, section 86A (relevant prices chosen by Scottish Ministers)
+      href: https://www.legislation.gov.uk/asp/2018/9/section/86A
+    - title: Social Security Assistance in Scotland - up-rating for inflation 2026-2027, sections 2 and 3 (September CPI and nearest 5p)
+      href: https://www.gov.scot/publications/social-security-assistance-scotland-up-rating-inflation-2026-27/pages/3/

policyengine_uk/parameters/gov/social_security_scotland/pawhp/amount/higher_shared_with_under_80.yaml

@@ -15,4 +15,20 @@ values:
 metadata:
   unit: currency-GBP
   label: PAWHP shared amount 80 and over, living with under 80
-  uprating: gov.economic_assumptions.indices.obr.consumer_price_index
+  # September CPI and nearest-5p rounding follow Scottish Ministers' current
+  # policy; s86A leaves the choice of relevant prices to Ministers.
+  # Apply each year's rise to the previous rounded rate each April.
+  uprating:
+    parameter: gov.benefit_uprating_cpi
+    at_defined_interval:
+      start: "0001-01-01"
+      end: "0002-01-01"
+      enactment: "0002-04-01"
+    rounding:
+      type: nearest
+      interval: 0.05
+  reference:
+    - title: Social Security (Scotland) Act 2018, section 86A (relevant prices chosen by Scottish Ministers)
+      href: https://www.legislation.gov.uk/asp/2018/9/section/86A
+    - title: Social Security Assistance in Scotland - up-rating for inflation 2026-2027, sections 2 and 3 (September CPI and nearest 5p)
+      href: https://www.gov.scot/publications/social-security-assistance-scotland-up-rating-inflation-2026-27/pages/3/

policyengine_uk/parameters/gov/social_security_scotland/pawhp/amount/lower.yaml

@@ -20,4 +20,20 @@ values:
 metadata:
   unit: currency-GBP
   label: PAWHP lower (under-80) amount
-  uprating: gov.economic_assumptions.indices.obr.consumer_price_index
+  # September CPI and nearest-5p rounding follow Scottish Ministers' current
+  # policy; s86A leaves the choice of relevant prices to Ministers.
+  # Apply each year's rise to the previous rounded rate each April.
+  uprating:
+    parameter: gov.benefit_uprating_cpi
+    at_defined_interval:
+      start: "0001-01-01"
+      end: "0002-01-01"
+      enactment: "0002-04-01"
+    rounding:
+      type: nearest
+      interval: 0.05
+  reference:
+    - title: Social Security (Scotland) Act 2018, section 86A (relevant prices chosen by Scottish Ministers)
+      href: https://www.legislation.gov.uk/asp/2018/9/section/86A
+    - title: Social Security Assistance in Scotland - up-rating for inflation 2026-2027, sections 2 and 3 (September CPI and nearest 5p)
+      href: https://www.gov.scot/publications/social-security-assistance-scotland-up-rating-inflation-2026-27/pages/3/

policyengine_uk/parameters/gov/social_security_scotland/pawhp/amount/lower_shared.yaml

@@ -15,4 +15,20 @@ values:
 metadata:
   unit: currency-GBP
   label: PAWHP shared amount under 80
-  uprating: gov.economic_assumptions.indices.obr.consumer_price_index
+  # September CPI and nearest-5p rounding follow Scottish Ministers' current
+  # policy; s86A leaves the choice of relevant prices to Ministers.
+  # Apply each year's rise to the previous rounded rate each April.
+  uprating:
+    parameter: gov.benefit_uprating_cpi
+    at_defined_interval:
+      start: "0001-01-01"
+      end: "0002-01-01"
+      enactment: "0002-04-01"
+    rounding:
+      type: nearest
+      interval: 0.05
+  reference:
+    - title: Social Security (Scotland) Act 2018, section 86A (relevant prices chosen by Scottish Ministers)
+      href: https://www.legislation.gov.uk/asp/2018/9/section/86A
+    - title: Social Security Assistance in Scotland - up-rating for inflation 2026-2027, sections 2 and 3 (September CPI and nearest 5p)
+      href: https://www.gov.scot/publications/social-security-assistance-scotland-up-rating-inflation-2026-27/pages/3/

policyengine_uk/parameters/gov/social_security_scotland/scottish_child_payment/amount.yaml

@@ -7,19 +7,31 @@ values:
   2024-04-01: 26.70
   2025-04-01: 27.15
   2026-04-01: 28.20
-  2027-04-01: 28.85
-  2028-04-01: 29.45
-  2029-04-01: 30.05
-  2030-04-01: 30.65
+  # Project from the last published rate. The January 2026 SFC forecasts
+  # for 2027-30 predate the September 2026 CPI outturn and are superseded
+  # here by the September-CPI projection, not treated as announced rates.
 metadata:
   unit: currency-GBP
   period: week
   label: Scottish Child Payment weekly amount
-  uprating: gov.economic_assumptions.indices.obr.consumer_price_index
+  # September CPI and nearest-5p rounding follow Scottish Ministers' current
+  # policy; s86A leaves the choice of relevant prices to Ministers.
+  # Apply each year's rise to the previous rounded rate each April.
+  uprating:
+    parameter: gov.benefit_uprating_cpi
+    at_defined_interval:
+      start: "0001-01-01"
+      end: "0002-01-01"
+      enactment: "0002-04-01"
+    rounding:
+      type: nearest
+      interval: 0.05
   reference:
+    - title: Social Security (Scotland) Act 2018, section 86A (relevant prices chosen by Scottish Ministers)
+      href: https://www.legislation.gov.uk/asp/2018/9/section/86A
+    - title: Social Security Assistance in Scotland - up-rating for inflation 2026-2027, sections 2 and 3 (September CPI and nearest 5p)
+      href: https://www.gov.scot/publications/social-security-assistance-scotland-up-rating-inflation-2026-27/pages/3/
     - title: The Scottish Child Payment Regulations 2020, Regulation 20
       href: https://www.legislation.gov.uk/ssi/2020/351/regulation/20
     - title: Scottish Government - Scottish Child Payment
       href: https://www.gov.scot/policies/social-security/scottish-child-payment/
-    - title: Scottish Fiscal Commission - Scotland's Economic and Fiscal Forecasts January 2026
-      href: https://fiscalcommission.scot/wp-content/uploads/2026/01/Scotlands-Economic-and-Fiscal-Forecasts-January-2026-revised-13-01-2026.pdf

policyengine_uk/tests/policy/baseline/gov/social_security_scotland/scottish_child_payment.yaml

@@ -277,7 +277,7 @@
     # [parent, child_1]
     scottish_child_payment: [0, 1466]
 
-- name: SCP with 2027 amount (£28.85/week)
+- name: SCP with 2027 September CPI projection (£29.20/week)
   period: 2027
   absolute_error_margin: 10
   input:
@@ -295,11 +295,11 @@
         members: [parent, child_1]
         region: SCOTLAND
   output:
-    # £28.85/week * 52 weeks = £1,500.20
+    # £28.20 * 1.035 rounded to 5p = £29.20/week; annualised over 52 weeks = £1,518.40
     # [parent, child_1]
-    scottish_child_payment: [0, 1500]
+    scottish_child_payment: [0, 1518.40]
 
-- name: SCP with 2028 amount (£29.45/week)
+- name: SCP with 2028 September CPI projection (£29.80/week)
   period: 2028
   absolute_error_margin: 10
   input:
@@ -317,9 +317,9 @@
         members: [parent, child_1]
         region: SCOTLAND
   output:
-    # £29.45/week * 52 weeks = £1,531.40
+    # £29.20 * 1.021 rounded to 5p = £29.80/week; annualised over 52 weeks = £1,549.60
     # [parent, child_1]
-    scottish_child_payment: [0, 1531]
+    scottish_child_payment: [0, 1549.60]
 
 - name: CTC no longer qualifies from 2025 (after April 2024)
   period: 2025

policyengine_uk/tests/policy/baseline/gov/social_security_scotland/september_cpi_uprating.yaml

@@ -0,0 +1,104 @@
+# April 2027 projections, not enacted 2027 rates. Scottish Ministers' current
+# policy is the previous September's CPI, rounded to the nearest 5p:
+# https://www.gov.scot/publications/social-security-assistance-scotland-up-rating-inflation-2026-27/pages/3/
+# September 2026 CPI was 3.5%; these expectations are hand-computed from the
+# enacted 2026 amounts, independently of the model's generated index.
+# Annual model periods use the fiscal-year parameter amounts.
+
+- name: Scottish Child Payment projects to 29.20 a week in April 2027
+  # 28.20 x 1.035 = 29.187 -> 29.20, then 29.20 x 365.25 / 7 = 1523.614286.
+  period: 2027
+  absolute_error_margin: 0.01
+  input:
+    people:
+      parent:
+        age: 30
+      child:
+        age: 5
+        would_claim_scp: true
+    benunits:
+      family:
+        members: [parent, child]
+        universal_credit: 5000
+    households:
+      household:
+        members: [parent, child]
+        country: SCOTLAND
+  output:
+    is_scp_eligible: [false, true]
+    scottish_child_payment: [0, 1518.40]
+
+- name: PAWHP higher full amount projects to 327.80 in April 2027
+  # 316.70 x 1.035 = 327.7845 -> 327.80.
+  period: 2027
+  absolute_error_margin: 0.01
+  input:
+    age: 82
+    country: SCOTLAND
+    pawhp_eligible: true
+    is_on_pawhp_relevant_benefit: true
+  output:
+    pension_age_winter_heating_payment: 327.80
+
+- name: PAWHP lower full amount projects to 218.55 in April 2027
+  # 211.15 x 1.035 = 218.54025 -> 218.55.
+  period: 2027
+  absolute_error_margin: 0.01
+  input:
+    age: 70
+    country: SCOTLAND
+    pawhp_eligible: true
+    is_on_pawhp_relevant_benefit: true
+  output:
+    pension_age_winter_heating_payment: 218.55
+
+- name: PAWHP shared amounts for mixed ages use September CPI in April 2027
+  # Under 80: 105.55 x 1.035 = 109.24425 -> 109.25.
+  # Over 80 beside under 80: 211.15 x 1.035 = 218.54025 -> 218.55.
+  period: 2027
+  absolute_error_margin: 0.01
+  input:
+    people:
+      younger:
+        age: 70
+        pawhp_eligible: true
+        is_on_pawhp_relevant_benefit: false
+      older:
+        age: 82
+        pawhp_eligible: true
+        is_on_pawhp_relevant_benefit: false
+    benunits:
+      couple:
+        members: [younger, older]
+    households:
+      household:
+        members: [younger, older]
+        country: SCOTLAND
+  output:
+    pension_age_winter_heating_payment: [109.25, 218.55]
+    pawhp: 327.80
+
+- name: PAWHP shared amount for both over 80 projects to 163.90 in April 2027
+  # 158.35 x 1.035 = 163.89225 -> 163.90 for each person.
+  period: 2027
+  absolute_error_margin: 0.01
+  input:
+    people:
+      first:
+        age: 82
+        pawhp_eligible: true
+        is_on_pawhp_relevant_benefit: false
+      second:
+        age: 85
+        pawhp_eligible: true
+        is_on_pawhp_relevant_benefit: false
+    benunits:
+      couple:
+        members: [first, second]
+    households:
+      household:
+        members: [first, second]
+        country: SCOTLAND
+  output:
+    pension_age_winter_heating_payment: [163.90, 163.90]
+    pawhp: 327.80

policyengine_uk/tests/policy/reforms/scp_baby_bonus/scottish_child_payment_baby_bonus.yaml

@@ -51,9 +51,9 @@
         members: [parent, toddler]
         region: SCOTLAND
   output:
-    # Standard rate only: £29.45/week * 52 = £1,531.40
+    # Standard rate only: £29.80/week * 52 = £1,549.60
     # [parent, toddler]
-    scottish_child_payment: [0, 1531]
+    scottish_child_payment: [0, 1549.60]
 
 - name: SCP baby bonus - mixed ages (2028)
   period: 2028
@@ -79,9 +79,9 @@
         region: SCOTLAND
   output:
     # Baby (age 0): £40.80/week total * 52 = £2,121.60
-    # Older child (age 5): £29.45/week * 52 = £1,531.40
+    # Older child (age 5): £29.80/week * 52 = £1,549.60
     # [parent, baby, older_child]
-    scottish_child_payment: [0, 2122, 1531]
+    scottish_child_payment: [0, 2122, 1549.60]
 
 - name: SCP baby bonus - not in Scotland (2028)
   period: 2028