Add improvements

changelog_entry.yaml

@@ -0,0 +1,7 @@
+- bump: minor
+  changes:
+    fixed:
+    - New benefit claimants are now accounted for in reforms.
+    added:
+    - Abolition switch for State Pension payments.
+    - Freeze switch for Pension Credit payments.

policyengine_uk/parameters/gov/contrib/abolish_state_pension.yaml

@@ -0,0 +1,6 @@
+description: Remove all State Pension payments.
+values:
+  2000-01-01: false
+metadata:
+  unit: bool
+  label: Abolish State Pension

policyengine_uk/parameters/gov/contrib/freeze_pension_credit.yaml

@@ -0,0 +1,6 @@
+description: Freeze Pension Credit payments. Set all Pension Credit payments to what they are under baseline policy.
+values:
+  2000-01-01: false
+metadata:
+  unit: currency-GBP
+  label: Freeze Pension Credit

policyengine_uk/parameters/gov/dwp/universal_credit/takeup.yaml

@@ -1,11 +1,5 @@
 description: Universal Credit takeup rate
 values:
-  2025-01-01: 0.8717
-  2024-01-01: 0.8637
-  2023-01-01: 0.8555
-  2022-01-01: 0.8472
-  2021-01-01: 0.8366
-  2020-01-01: 0.869
-  2019-01-01: 0.7447
+  2019-01-01: 0.63 # From PolicyEngine microsimulation (UC claimants vs eligible households).
 metadata:
   unit: /1

policyengine_uk/system.py

@@ -92,11 +92,14 @@ def __init__(self, *args, **kwargs):
 
         # Labor supply responses
 
-        employment_income = self.get_holder("employment_income")
-        for known_period in employment_income.get_known_periods():
-            array = employment_income.get_array(known_period)
-            self.set_input("employment_income_before_lsr", known_period, array)
-            employment_income.delete_arrays(known_period)
+        for simulation in list(self.branches.values()) + [self]:
+            employment_income = simulation.get_holder("employment_income")
+            for known_period in employment_income.get_known_periods():
+                array = employment_income.get_array(known_period)
+                simulation.set_input(
+                    "employment_income_before_lsr", known_period, array
+                )
+                employment_income.delete_arrays(known_period)
 
 
 class IndividualSim(CoreIndividualSim):  # Deprecated

policyengine_uk/variables/gov/dwp/housing_benefit.py

@@ -240,8 +240,7 @@ class housing_benefit_pre_benefit_cap(Variable):
     def formula(benunit, period, parameters):
         entitlement = benunit("housing_benefit_entitlement", period)
         eligible = benunit("housing_benefit_eligible", period)
-        would_claim = benunit("would_claim_HB", period)
-        return would_claim * entitlement * eligible
+        return entitlement * eligible
 
 
 class housing_benefit(Variable):
@@ -250,6 +249,7 @@ class housing_benefit(Variable):
     definition_period = YEAR
     value_type = float
     unit = GBP
+    defined_for = "would_claim_HB"
 
     def formula(benunit, period, parameters):
         housing_benefit_entitlement = benunit(
@@ -269,3 +269,9 @@ class baseline_housing_benefit_entitlement(Variable):
     definition_period = YEAR
     value_type = float
     unit = GBP
+
+    def formula(benunit, period, parameters):
+        if benunit.simulation.baseline is None:
+            return 1
+        baseline = benunit.simulation.baseline.populations["benunit"]
+        return baseline("housing_benefit_entitlement", period)

policyengine_uk/variables/gov/dwp/pension_credit/pension_credit.py

@@ -8,5 +8,15 @@ class pension_credit(Variable):
     value_type = float
     unit = GBP
     reference = "https://www.legislation.gov.uk/ukpga/2002/16/contents"
-    defined_for = "would_claim_pc"
-    adds = ["pension_credit_entitlement"]
+
+    def formula(benunit, period, parameters):
+        entitlement = benunit("pension_credit_entitlement", period)
+        would_claim = benunit("would_claim_pc", period)
+        amount = entitlement * would_claim
+
+        freeze = parameters(period).gov.contrib.freeze_pension_credit
+        baseline = benunit.simulation.baseline
+        if freeze and baseline is not None:
+            return baseline.populations["benunit"]("pension_credit", period)
+        else:
+            return amount

policyengine_uk/variables/gov/dwp/tax_credits.py

@@ -600,9 +600,21 @@ class baseline_wtc_entitlement(Variable):
     definition_period = YEAR
     value_type = float
 
+    def formula(benunit, period, parameters):
+        if benunit.simulation.baseline is None:
+            return 1
+        baseline = benunit.simulation.baseline.populations["benunit"]
+        return baseline("wtc_entitlement", period)
+
 
 class baseline_ctc_entitlement(Variable):
     label = "Receives Child Tax Credit (baseline)"
     entity = BenUnit
     definition_period = YEAR
     value_type = float
+
+    def formula(benunit, period, parameters):
+        if benunit.simulation.baseline is None:
+            return 1
+        baseline = benunit.simulation.baseline.populations["benunit"]
+        return baseline("wtc_entitlement", period)

policyengine_uk/variables/gov/dwp/universal_credit.py

@@ -34,12 +34,56 @@ def formula(benunit, period, parameters):
         current_uc_claimant = (
             add(benunit, period, ["universal_credit_reported"]) > 0
         )
+        brought_into_claim = benunit(
+            "is_brought_into_uc_claimant_status", period
+        )
         is_in_microsimulation = hasattr(benunit.simulation, "dataset")
         if is_in_microsimulation:
-            return current_uc_claimant
+            return current_uc_claimant | brought_into_claim
         return True
 
 
+class is_brought_into_uc_claimant_status(Variable):
+    label = "brought into UC claimant status"
+    entity = BenUnit
+    definition_period = YEAR
+    value_type = bool
+
+    def formula(benunit, period, parameters):
+        if benunit.simulation.baseline is None:
+            return False
+        uc_entitled = benunit("is_uc_entitled", period)
+        uc_entitled_baseline = benunit("is_uc_entitled_baseline", period)
+        takeup = parameters(period).gov.dwp.universal_credit.takeup
+        takes_up_given_new_claimant = random(benunit) < takeup
+        return (
+            uc_entitled & ~uc_entitled_baseline & takes_up_given_new_claimant
+        )
+
+
+class is_uc_entitled(Variable):
+    label = "meets the means test for Universal Credit"
+    entity = BenUnit
+    definition_period = YEAR
+    value_type = bool
+
+    def formula(benunit, period, parameters):
+        uc = benunit("universal_credit_pre_benefit_cap", period)
+        return uc > 0
+
+
+class is_uc_entitled_baseline(Variable):
+    label = "meets the means test for Universal Credit under baseline law"
+    entity = BenUnit
+    definition_period = YEAR
+    value_type = bool
+
+    def formula(benunit, period, parameters):
+        baseline = benunit.simulation.baseline.populations["benunit"]
+        uc = baseline("universal_credit_pre_benefit_cap", period)
+        return uc > 0
+
+
 class is_UC_eligible(Variable):
     value_type = bool
     entity = BenUnit
@@ -581,7 +625,6 @@ class universal_credit_pre_benefit_cap(Variable):
     category = BENEFIT
     adds = ["UC_maximum_amount"]
     subtracts = ["UC_income_reduction"]
-    defined_for = "would_claim_UC"
 
 
 class universal_credit(Variable):
@@ -590,6 +633,7 @@ class universal_credit(Variable):
     definition_period = YEAR
     value_type = float
     unit = GBP
+    defined_for = "would_claim_UC"
 
     def formula(benunit, period, parameters):
         uc_max_entitlement = benunit(

policyengine_uk/variables/input/income.py

@@ -51,6 +51,8 @@ class state_pension(Variable):
 
     def formula(person, period, parameters):
         gov = parameters(period).gov
+        if gov.contrib.abolish_state_pension:
+            return 0
         relative_increase = gov.contrib.cec.state_pension_increase
         uprating = 1 + relative_increase
         sp = gov.dwp.state_pension