[1] - added the metrics of Budgetary impact by program.

policyengine/economic_impact/budgetary_impact/by_program/by_program.py

@@ -0,0 +1,192 @@
+from policyengine.economic_impact.base_metric_calculator import BaseMetricCalculator
+from policyengine_uk import Microsimulation
+
+class IncomeTax(BaseMetricCalculator):
+    def __init__(self, baseline: Microsimulation, reformed: Microsimulation, default_period: int = 2024) -> None:
+        super().__init__(baseline, reformed, default_period)
+        self.baseline = baseline
+        self.reformed = reformed
+
+    def calculate(self):
+
+        baseline = self.baseline.calculate("income_tax", map_to="household").sum()
+        reform = self.reformed.calculate("income_tax", map_to="household").sum()
+
+        change = ((reform - baseline) / baseline) * 100
+
+        return {
+            "baseline": round(baseline,2),
+            "reform": round(reform,2),
+            "change": round(change,1)
+        }
+
+class NationalInsurance(BaseMetricCalculator):
+    def __init__(self, baseline: Microsimulation, reformed: Microsimulation, default_period: int = 2024) -> None:
+        super().__init__(baseline, reformed, default_period)
+        self.baseline = baseline
+        self.reformed = reformed
+
+    def calculate(self):
+
+        baseline = self.baseline.calculate("national_insurance", map_to="household").sum()
+        reform = self.reformed.calculate("national_insurance", map_to="household").sum()
+
+        change = ((reform - baseline) / baseline) * 100
+
+        return {
+            "baseline": round(baseline,2),
+            "reform": round(reform,2),
+            "change": round(change,1)
+        }
+
+class Vat(BaseMetricCalculator):
+    def __init__(self, baseline: Microsimulation, reformed: Microsimulation, default_period: int = 2024) -> None:
+        super().__init__(baseline, reformed, default_period)
+        self.baseline = baseline
+        self.reformed = reformed
+
+    def calculate(self):
+
+        baseline = self.baseline.calculate("vat", map_to="household").sum()
+        reform = self.reformed.calculate("vat", map_to="household").sum()
+
+        change = ((reform - baseline) / baseline) * 100
+
+        return {
+            "baseline": round(baseline,2),
+            "reform": round(reform,2),
+            "change": round(change,1)
+        }
+
+class CouncilTax(BaseMetricCalculator):
+    def __init__(self, baseline: Microsimulation, reformed: Microsimulation, default_period: int = 2024) -> None:
+        super().__init__(baseline, reformed, default_period)
+        self.baseline = baseline
+        self.reformed = reformed
+
+    def calculate(self):
+
+        baseline = self.baseline.calculate("council_tax", map_to="household").sum()
+        reform = self.reformed.calculate("council_tax", map_to="household").sum()
+
+        change = ((reform - baseline) / baseline) * 100
+
+        return {
+            "baseline": round(baseline,2),
+            "reform": round(reform,2),
+            "change": round(change,1)
+        }
+
+class FuelDuty(BaseMetricCalculator):
+    def __init__(self, baseline: Microsimulation, reformed: Microsimulation, default_period: int = 2024) -> None:
+        super().__init__(baseline, reformed, default_period)
+        self.baseline = baseline
+        self.reformed = reformed
+
+    def calculate(self):
+
+        baseline = self.baseline.calculate("fuel_duty", map_to="household").sum()
+        reform = self.reformed.calculate("fuel_duty", map_to="household").sum()
+
+        change = ((reform - baseline) / baseline) * 100
+
+        return {
+            "baseline": round(baseline,2),
+            "reform": round(reform,2),
+            "change": round(change,1)
+        }
+
+class TaxCredits(BaseMetricCalculator):
+    def __init__(self, baseline: Microsimulation, reformed: Microsimulation, default_period: int = 2024) -> None:
+        super().__init__(baseline, reformed, default_period)
+        self.baseline = baseline
+        self.reformed = reformed
+
+    def calculate(self):
+
+        baseline = self.baseline.calculate("tax_credits", map_to="household").sum() * -1
+        reform = self.reformed.calculate("tax_credits", map_to="household").sum() * -1
+
+        change = ((reform - baseline) / baseline) * 100
+
+        return {
+            "baseline": round(baseline,2),
+            "reform": round(reform,2),
+            "change": round(change,1)
+        }
+
+class UniversalCredit(BaseMetricCalculator):
+    def __init__(self, baseline: Microsimulation, reformed: Microsimulation, default_period: int = 2024) -> None:
+        super().__init__(baseline, reformed, default_period)
+        self.baseline = baseline
+        self.reformed = reformed
+
+    def calculate(self):
+
+        baseline = self.baseline.calculate("universal_credit", map_to="household").sum() * -1
+        reform = self.reformed.calculate("universal_credit", map_to="household").sum() * -1
+
+        change = ((reform - baseline) / baseline) * 100 
+
+        return {
+            "baseline": round(baseline,2),
+            "reform": round(reform,2),
+            "change": round(change,1)
+        }
+
+class ChildBenefit(BaseMetricCalculator):
+    def __init__(self, baseline: Microsimulation, reformed: Microsimulation, default_period: int = 2024) -> None:
+        super().__init__(baseline, reformed, default_period)
+        self.baseline = baseline
+        self.reformed = reformed
+
+    def calculate(self):
+
+        baseline = self.baseline.calculate("child_benefit", map_to="household").sum() * -1
+        reform = self.reformed.calculate("child_benefit", map_to="household").sum() * -1
+
+        change = ((reform - baseline) / baseline) * 100 
+
+        return {
+            "baseline": round(baseline,2),
+            "reform": round(reform,2),
+            "change": round(change,1)
+        }
+
+class StatePension(BaseMetricCalculator):
+    def __init__(self, baseline: Microsimulation, reformed: Microsimulation, default_period: int = 2024) -> None:
+        super().__init__(baseline, reformed, default_period)
+        self.baseline = baseline
+        self.reformed = reformed
+
+    def calculate(self):
+
+        baseline = self.baseline.calculate("state_pension", map_to="household").sum()  * -1
+        reform = self.reformed.calculate("state_pension", map_to="household").sum()  * -1
+
+        change = ((reform - baseline) / baseline) * 100 
+
+        return {
+            "baseline": round(baseline,2),
+            "reform": round(reform,2),
+            "change": round(change,1)
+        }
+
+class PensionCredit(BaseMetricCalculator):
+    def __init__(self, baseline: Microsimulation, reformed: Microsimulation, default_period: int = 2024) -> None:
+        super().__init__(baseline, reformed, default_period)
+        self.baseline = baseline
+        self.reformed = reformed
+
+    def calculate(self):
+
+        baseline = self.baseline.calculate("pension_credit", map_to="household").sum()  * -1
+        reform = self.reformed.calculate("pension_credit", map_to="household").sum()  * -1
+
+        change = ((reform - baseline) / baseline) * 100
+
+        return {
+            "baseline": round(baseline,2),
+            "reform": round(reform,2),
+            "change": round(change,1)
+        }

policyengine/economic_impact/economic_impact.py

@@ -22,6 +22,20 @@
     FemalePoverty as DeepFemalePoverty,
     AllPoverty as DeepGenderAllPoverty
 )
+
+from .budgetary_impact.by_program.by_program import (
+    IncomeTax, 
+    NationalInsurance, 
+    Vat, 
+    CouncilTax, 
+    FuelDuty, 
+    TaxCredits, 
+    UniversalCredit, 
+    ChildBenefit, 
+    StatePension, 
+    PensionCredit
+)
+
 from typing import Dict
 
 class EconomicImpact:
@@ -55,6 +69,16 @@ def __init__(self, reform: dict, country: str) -> None:
 
         # Set up metric calculators
         self.metric_calculators: Dict[str, object] = {
+            "budgetary/by_program/income_tax" : IncomeTax(self.baseline, self.reformed),
+            "budgetary/by_program/national_insurance" : NationalInsurance(self.baseline, self.reformed),
+            "budgetary/by_program/vat" : Vat(self.baseline, self.reformed),
+            "budgetary/by_program/council_tax" : CouncilTax(self.baseline, self.reformed),
+            "budgetary/by_program/fuel_duty" : FuelDuty(self.baseline, self.reformed),
+            "budgetary/by_program/tax_credits" : TaxCredits(self.baseline, self.reformed),
+            "budgetary/by_program/universal_credits" : UniversalCredit(self.baseline, self.reformed),
+            "budgetary/by_program/child_benefits" : ChildBenefit(self.baseline, self.reformed),
+            "budgetary/by_program/state_pension" : StatePension(self.baseline, self.reformed),
+            "budgetary/by_program/pension_credit" : PensionCredit(self.baseline, self.reformed),
             "inequality/gini": GiniCalculator(self.baseline, self.reformed),
             "inequality/top_1_pct_share": Top1PctShareCalculator(self.baseline, self.reformed),
             "inequality/top_10_pct_share": Top10PctShareCalculator(self.baseline, self.reformed),

policyengine/tests/economic_impact/budgetary_impact/by_program/by_program.yaml

@@ -0,0 +1,100 @@
+# by_program
+- test_income_tax:
+    reform:
+      gov.hmrc.income_tax.rates.uk[0].rate:
+        "2024-01-01.2100-12-31": 0.55
+    country: uk
+    expected:
+      baseline: 291090070166.62
+      reform: 496242053771.2
+      change: 70.5
+
+- test_national_insurance:
+    reform:
+      gov.hmrc.income_tax.rates.uk[0].rate:
+        "2024-01-01.2100-12-31": 0.55
+    country: uk
+    expected:
+      baseline: 50826792606.89
+      reform: 50826792606.89
+      change: 0.0
+
+- test_vat:
+    reform:
+      gov.hmrc.income_tax.rates.uk[0].rate:
+        "2024-01-01.2100-12-31": 0.55
+    country: uk
+    expected:
+      baseline: 175581776889.21
+      reform: 175581776889.21
+      change: 0.0
+
+- test_council_tax:
+    reform:
+      gov.hmrc.income_tax.rates.uk[0].rate:
+        "2024-01-01.2100-12-31": 0.55
+    country: uk
+    expected:
+      baseline: 47861314826.79
+      reform: 47861314826.79
+      change: 0.0
+
+- test_fuel_duty:
+    reform:
+      gov.hmrc.income_tax.rates.uk[0].rate:
+        "2024-01-01.2100-12-31": 0.55
+    country: uk
+    expected:
+      baseline: 28019829809.09
+      reform: 28019829809.09
+      change: 0.0
+
+- test_tax_credits:
+    reform:
+      gov.hmrc.income_tax.rates.uk[0].rate:
+        "2024-01-01.2100-12-31": 0.55
+    country: uk
+    expected:
+      baseline: -208150256.01
+      reform: -308166663.98
+      change: 48.1
+
+- test_universal_credits:
+    reform:
+      gov.hmrc.income_tax.rates.uk[0].rate:
+        "2024-01-01.2100-12-31": 0.55
+    country: uk
+    expected:
+      baseline: -72209672284.1
+      reform: -73780445681.08
+      change: 2.2
+
+- test_child_benefits:
+    reform:
+      gov.hmrc.income_tax.rates.uk[0].rate:
+        "2024-01-01.2100-12-31": 0.55
+    country: uk
+    expected:
+      baseline: -15975002346.41
+      reform: -15975002346.41
+      change: -0.0
+
+- test_state_pension:
+    reform:
+      gov.hmrc.income_tax.rates.uk[0].rate:
+        "2024-01-01.2100-12-31": 0.55
+    country: uk
+    expected:
+      baseline: -127240166697.26
+      reform: -127240166697.26
+      change: -0.0
+
+- test_pension_credit:
+    reform:
+      gov.hmrc.income_tax.rates.uk[0].rate:
+        "2024-01-01.2100-12-31": 0.55
+    country: uk
+    expected:
+      baseline: -2000983943.05
+      reform: -2181135212.4
+      change: 9.0

policyengine/tests/economic_impact/budgetary_impact/by_program/test_by_program.py

@@ -0,0 +1,53 @@
+import pytest
+import yaml
+import os
+from policyengine import EconomicImpact
+
+def assert_dict_approx_equal(actual, expected, tolerance=1e-4):
+    for key in expected:
+        assert abs(actual[key] - expected[key]) < tolerance, f"Key {key}: expected {expected[key]}, got {actual[key]}"
+
+
+yaml_file_path = "policyengine/tests/economic_impact/budgetary_impact/by_program/by_program.yaml"
+
+# Check if the file exists
+if not os.path.exists(yaml_file_path):
+    raise FileNotFoundError(f"The YAML file does not exist at: {yaml_file_path}")
+
+with open(yaml_file_path, 'r') as file:
+    test_cases = yaml.safe_load(file)
+
+@pytest.mark.parametrize("test_case", test_cases)
+def test_economic_impact(test_case):
+    test_name = list(test_case.keys())[0]
+    test_data = test_case[test_name]
+
+    economic_impact = EconomicImpact(test_data['reform'], test_data['country'])
+
+    if 'income_tax' in test_name:
+        result = economic_impact.calculate("budgetary/by_program/income_tax")
+    elif 'national_insurance' in test_name:
+        result = economic_impact.calculate("budgetary/by_program/national_insurance")
+    elif 'vat' in test_name:
+        result = economic_impact.calculate("budgetary/by_program/vat")
+    elif 'council_tax' in test_name:
+        result = economic_impact.calculate("budgetary/by_program/council_tax")
+    elif 'fuel_duty' in test_name:
+        result = economic_impact.calculate("budgetary/by_program/fuel_duty")
+    elif 'tax_credits' in test_name:
+        result = economic_impact.calculate("budgetary/by_program/tax_credits")
+    elif 'universal_credits' in test_name:
+        result = economic_impact.calculate("budgetary/by_program/universal_credits")
+    elif 'child_benefits' in test_name:
+        result = economic_impact.calculate("budgetary/by_program/child_benefits")
+    elif 'state_pension' in test_name:
+        result = economic_impact.calculate("budgetary/by_program/state_pension")
+    elif 'pension_credit' in test_name:
+        result = economic_impact.calculate("budgetary/by_program/pension_credit")
+    else:
+        pytest.fail(f"Unknown test case: {test_name}")
+
+    assert_dict_approx_equal(result, test_data['expected'])
+
+if __name__ == "__main__":
+    pytest.main([__file__])