Add historical Housing Benefit non-dependant deduction rates

changelog.d/hb-nondep-history.fixed.md

@@ -0,0 +1,2 @@
+- Added the enacted 2015 to 2017 Housing Benefit non-dependant deduction thresholds and amounts instead of backdating the 2018 scale.
+- Corrected the 2018 scale commencement so the 2018-19 Housing Benefit and Council Tax Reduction deductions use the April rates.

policyengine_uk/parameters/gov/dwp/housing_benefit/non_dep_deduction/amount.yaml

@@ -7,17 +7,58 @@ description: The following amount is provided for individuals under the Housing
 # Deduction amounts rise by September CPI. Income bands follow earnings in
 # practice; retain their previous lagged calendar-year CPI projection as a
 # placeholder until the earnings-linked uprating model covers them.
+# SI 2018/281 art 1(2)(h): the 2018 rates commence on 2 April for
+# weekly rents (1 April for other rent periods). This weekly scale uses
+# 2 April; both dates precede the fiscal-year sample at 30 April.
 brackets:
 - threshold:
     metadata:
       uprating: gov.economic_assumptions.indices.obr.lagged_cpi
     values:
-      2018-06-18: 0
+      2015-04-01:
+        value: 0
+        reference:
+          - title: 2015 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2015/457/article/18/made
+      2016-04-01:
+        value: 0
+        reference:
+          - title: 2016 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2016/242/regulation/5/made
+      2017-04-01:
+        value: 0
+        reference:
+          - title: 2017 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2017/260/article/22/made
+      2018-04-02:
+        value: 0
+        reference:
+          - title: The Social Security Benefits Up-rating Order 2018 (SI 2018/281), articles 1(2)(h), 23(3) and 24(3)
+            href: https://www.legislation.gov.uk/uksi/2018/281/pdfs/uksi_20180281_en.pdf
   amount:
     metadata:
       uprating: gov.benefit_uprating_cpi
     values:
-      2018-06-18: 15.25
+      2015-04-01:
+        value: 14.55
+        reference:
+          - title: 2015 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2015/457/article/18/made
+      2016-04-01:
+        value: 14.65
+        reference:
+          - title: 2016 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2016/242/regulation/5/made
+      2017-04-01:
+        value: 14.8
+        reference:
+          - title: 2017 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2017/260/article/22/made
+      2018-04-02:
+        value: 15.25
+        reference:
+          - title: The Social Security Benefits Up-rating Order 2018 (SI 2018/281), articles 1(2)(h), 23(3) and 24(3)
+            href: https://www.legislation.gov.uk/uksi/2018/281/pdfs/uksi_20180281_en.pdf
       2019-04-01: 15.6
       2020-04-01: 15.85
       2021-04-01: 15.95
@@ -30,7 +71,26 @@ brackets:
     metadata:
       uprating: gov.economic_assumptions.indices.obr.lagged_cpi
     values:
-      2018-06-18: 139
+      2015-04-01:
+        value: 129
+        reference:
+          - title: 2015 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2015/457/article/18/made
+      2016-04-01:
+        value: 133
+        reference:
+          - title: 2016 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2016/242/regulation/5/made
+      2017-04-01:
+        value: 136
+        reference:
+          - title: 2017 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2017/260/article/22/made
+      2018-04-02:
+        value: 139
+        reference:
+          - title: The Social Security Benefits Up-rating Order 2018 (SI 2018/281), articles 1(2)(h), 23(3) and 24(3)
+            href: https://www.legislation.gov.uk/uksi/2018/281/pdfs/uksi_20180281_en.pdf
       2019-04-01: 143
       2020-04-01: 149
       2022-04-01: 154
@@ -42,7 +102,26 @@ brackets:
     metadata:
       uprating: gov.benefit_uprating_cpi
     values:
-      2018-06-18: 35
+      2015-04-01:
+        value: 33.4
+        reference:
+          - title: 2015 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2015/457/article/18/made
+      2016-04-01:
+        value: 33.65
+        reference:
+          - title: 2016 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2016/242/regulation/5/made
+      2017-04-01:
+        value: 34
+        reference:
+          - title: 2017 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2017/260/article/22/made
+      2018-04-02:
+        value: 35
+        reference:
+          - title: The Social Security Benefits Up-rating Order 2018 (SI 2018/281), articles 1(2)(h), 23(3) and 24(3)
+            href: https://www.legislation.gov.uk/uksi/2018/281/pdfs/uksi_20180281_en.pdf
       2019-04-01: 35.85
       2020-04-01: 36.45
       2021-04-01: 36.65
@@ -55,7 +134,26 @@ brackets:
     metadata:
       uprating: gov.economic_assumptions.indices.obr.lagged_cpi
     values:
-      2018-06-18: 204
+      2015-04-01:
+        value: 189
+        reference:
+          - title: 2015 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2015/457/article/18/made
+      2016-04-01:
+        value: 195
+        reference:
+          - title: 2016 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2016/242/regulation/5/made
+      2017-04-01:
+        value: 200
+        reference:
+          - title: 2017 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2017/260/article/22/made
+      2018-04-02:
+        value: 204
+        reference:
+          - title: The Social Security Benefits Up-rating Order 2018 (SI 2018/281), articles 1(2)(h), 23(3) and 24(3)
+            href: https://www.legislation.gov.uk/uksi/2018/281/pdfs/uksi_20180281_en.pdf
       2019-04-01: 209
       2020-04-01: 217
       2022-04-01: 224
@@ -67,7 +165,26 @@ brackets:
     metadata:
       uprating: gov.benefit_uprating_cpi
     values:
-      2018-06-18: 48.05
+      2015-04-01:
+        value: 45.85
+        reference:
+          - title: 2015 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2015/457/article/18/made
+      2016-04-01:
+        value: 46.2
+        reference:
+          - title: 2016 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2016/242/regulation/5/made
+      2017-04-01:
+        value: 46.65
+        reference:
+          - title: 2017 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2017/260/article/22/made
+      2018-04-02:
+        value: 48.05
+        reference:
+          - title: The Social Security Benefits Up-rating Order 2018 (SI 2018/281), articles 1(2)(h), 23(3) and 24(3)
+            href: https://www.legislation.gov.uk/uksi/2018/281/pdfs/uksi_20180281_en.pdf
       2019-04-01: 49.2
       2020-04-01: 50.05
       2021-04-01: 50.3
@@ -80,7 +197,26 @@ brackets:
     metadata:
       uprating: gov.economic_assumptions.indices.obr.lagged_cpi
     values:
-      2018-06-18: 265
+      2015-04-01:
+        value: 246
+        reference:
+          - title: 2015 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2015/457/article/18/made
+      2016-04-01:
+        value: 253
+        reference:
+          - title: 2016 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2016/242/regulation/5/made
+      2017-04-01:
+        value: 259
+        reference:
+          - title: 2017 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2017/260/article/22/made
+      2018-04-02:
+        value: 265
+        reference:
+          - title: The Social Security Benefits Up-rating Order 2018 (SI 2018/281), articles 1(2)(h), 23(3) and 24(3)
+            href: https://www.legislation.gov.uk/uksi/2018/281/pdfs/uksi_20180281_en.pdf
       2019-04-01: 272
       2020-04-01: 283
       2022-04-01: 292
@@ -92,7 +228,26 @@ brackets:
     metadata:
       uprating: gov.benefit_uprating_cpi
     values:
-      2018-06-18: 78.65
+      2015-04-01:
+        value: 75.05
+        reference:
+          - title: 2015 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2015/457/article/18/made
+      2016-04-01:
+        value: 75.6
+        reference:
+          - title: 2016 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2016/242/regulation/5/made
+      2017-04-01:
+        value: 76.35
+        reference:
+          - title: 2017 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2017/260/article/22/made
+      2018-04-02:
+        value: 78.65
+        reference:
+          - title: The Social Security Benefits Up-rating Order 2018 (SI 2018/281), articles 1(2)(h), 23(3) and 24(3)
+            href: https://www.legislation.gov.uk/uksi/2018/281/pdfs/uksi_20180281_en.pdf
       2019-04-01: 80.55
       2020-04-01: 81.9
       2021-04-01: 82.3
@@ -105,7 +260,26 @@ brackets:
     metadata:
       uprating: gov.economic_assumptions.indices.obr.lagged_cpi
     values:
-      2018-06-18: 354
+      2015-04-01:
+        value: 328
+        reference:
+          - title: 2015 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2015/457/article/18/made
+      2016-04-01:
+        value: 338
+        reference:
+          - title: 2016 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2016/242/regulation/5/made
+      2017-04-01:
+        value: 346
+        reference:
+          - title: 2017 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2017/260/article/22/made
+      2018-04-02:
+        value: 354
+        reference:
+          - title: The Social Security Benefits Up-rating Order 2018 (SI 2018/281), articles 1(2)(h), 23(3) and 24(3)
+            href: https://www.legislation.gov.uk/uksi/2018/281/pdfs/uksi_20180281_en.pdf
       2019-04-01: 363
       2020-04-01: 377
       2022-04-01: 389
@@ -117,7 +291,26 @@ brackets:
     metadata:
       uprating: gov.benefit_uprating_cpi
     values:
-      2018-06-18: 89.55
+      2015-04-01:
+        value: 85.45
+        reference:
+          - title: 2015 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2015/457/article/18/made
+      2016-04-01:
+        value: 86.1
+        reference:
+          - title: 2016 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2016/242/regulation/5/made
+      2017-04-01:
+        value: 86.95
+        reference:
+          - title: 2017 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2017/260/article/22/made
+      2018-04-02:
+        value: 89.55
+        reference:
+          - title: The Social Security Benefits Up-rating Order 2018 (SI 2018/281), articles 1(2)(h), 23(3) and 24(3)
+            href: https://www.legislation.gov.uk/uksi/2018/281/pdfs/uksi_20180281_en.pdf
       2019-04-01: 91.7
       2020-04-01: 93.25
       2021-04-01: 93.7
@@ -130,7 +323,26 @@ brackets:
     metadata:
       uprating: gov.economic_assumptions.indices.obr.lagged_cpi
     values:
-      2018-06-18: 439
+      2015-04-01:
+        value: 408
+        reference:
+          - title: 2015 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2015/457/article/18/made
+      2016-04-01:
+        value: 420
+        reference:
+          - title: 2016 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2016/242/regulation/5/made
+      2017-04-01:
+        value: 430
+        reference:
+          - title: 2017 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2017/260/article/22/made
+      2018-04-02:
+        value: 439
+        reference:
+          - title: The Social Security Benefits Up-rating Order 2018 (SI 2018/281), articles 1(2)(h), 23(3) and 24(3)
+            href: https://www.legislation.gov.uk/uksi/2018/281/pdfs/uksi_20180281_en.pdf
       2019-04-01: 451
       2020-04-01: 469
       2022-04-01: 484
@@ -142,7 +354,26 @@ brackets:
     metadata:
       uprating: gov.benefit_uprating_cpi
     values:
-      2018-06-18: 98.3
+      2015-04-01:
+        value: 93.8
+        reference:
+          - title: 2015 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2015/457/article/18/made
+      2016-04-01:
+        value: 94.5
+        reference:
+          - title: 2016 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2016/242/regulation/5/made
+      2017-04-01:
+        value: 95.45
+        reference:
+          - title: 2017 Housing Benefit non-dependant deduction uprating
+            href: https://www.legislation.gov.uk/uksi/2017/260/article/22/made
+      2018-04-02:
+        value: 98.3
+        reference:
+          - title: The Social Security Benefits Up-rating Order 2018 (SI 2018/281), articles 1(2)(h), 23(3) and 24(3)
+            href: https://www.legislation.gov.uk/uksi/2018/281/pdfs/uksi_20180281_en.pdf
       2019-04-01: 100.65
       2020-04-01: 102.35
       2021-04-01: 102.85

policyengine_uk/tests/policy/baseline/finance/benefit/family/housing_benefit/non_dep_deduction/household_benefits_individual_non_dep_deduction.yaml

@@ -3,6 +3,18 @@
 # 19.65; £183-265.99 45.15; £266-347.99 62.00; £348-462.99 101.35;
 # £463-576.99 115.45; £577 and above 126.65.
 
+- name: The 2018 fiscal year uses the April non-dependant deduction in HB and CTR
+  # SI 2018/281 arts 23(3)(b), 24(3)(b), and 1(2)(h): £15.25 from
+  # 2 April for weekly rent (1 April otherwise), before the 30 April sample.
+  period: 2018
+  input:
+    housing_benefit_individual_non_dep_deduction_eligible: true
+    council_tax_reduction_individual_non_dep_deduction_eligible: true
+    total_income: 5_200 # £100 a week
+  output:
+    household_benefits_individual_non_dep_deduction: 793
+    council_tax_reduction_individual_non_dep_deduction: 793
+
 - name: Reduced rent without LHA
   period: 2025
   input: