Merge pull request #25 from masterismail/WinnersandLosers

added winners and losers metrics

policyengine/economic_impact/economic_impact.py

@@ -42,6 +42,9 @@
     TaxRevenueImpact
 )
 
+from .winners_and_losers.by_income_decile.by_income_decile import ByIncomeDecile
+from .winners_and_losers.by_wealth_decile.by_wealth_decile import ByWealthDecile
+
 from typing import Dict
 
 class EconomicImpact:
@@ -105,6 +108,8 @@ def __init__(self, reform: dict, country: str) -> None:
             "poverty/deep/male": DeepMalePoverty(self.baseline, self.reformed),
             "poverty/deep/female": DeepFemalePoverty(self.baseline, self.reformed),
             "poverty/deep/gender/all": DeepGenderAllPoverty(self.baseline, self.reformed),
+            "winners_and_losers/by_income_decile": ByIncomeDecile(self.baseline, self.reformed),
+            "winners_and_losers/by_wealth_decile": ByWealthDecile(self.baseline, self.reformed),
 
         }
 

policyengine/economic_impact/winners_and_losers/by_income_decile/by_income_decile.py

@@ -0,0 +1,55 @@
+from policyengine.economic_impact.base_metric_calculator import BaseMetricCalculator
+from policyengine_uk import Microsimulation
+from microdf import MicroDataFrame, MicroSeries
+import numpy as np
+
+class ByIncomeDecile(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_income = MicroSeries(
+            self.baseline.calculate("household_net_income"), weights=self.baseline.calculate("household_weight")
+        )
+        reform_income = MicroSeries(
+            self.reformed.calculate("household_net_income"), weights=baseline_income.weights
+        )
+        people = MicroSeries(
+            self.baseline.calculate("household_count_people"), weights=baseline_income.weights
+        )
+        decile = MicroSeries(self.baseline.calculate("household_income_decile")).values
+        absolute_change = (reform_income - baseline_income).values
+        capped_baseline_income = np.maximum(baseline_income.values, 1)
+        capped_reform_income = (
+            np.maximum(reform_income.values, 1) + absolute_change
+        )
+        income_change = (
+            capped_reform_income - capped_baseline_income
+        ) / capped_baseline_income
+
+        outcome_groups = {}
+        all_outcomes = {}
+        BOUNDS = [-np.inf, -0.05, -1e-3, 1e-3, 0.05, np.inf]
+        LABELS = [
+            "Lose more than 5%",
+            "Lose less than 5%",
+            "No change",
+            "Gain less than 5%",
+            "Gain more than 5%",
+        ]
+        for lower, upper, label in zip(BOUNDS[:-1], BOUNDS[1:], LABELS):
+            outcome_groups[label] = []
+            for i in range(1, 11):
+                in_decile = decile == i
+                in_group = (income_change > lower) & (income_change <= upper)
+                in_both = in_decile & in_group
+                outcome_groups[label].append(
+                    round(float(people[in_both].sum() / people[in_decile].sum()) * 100, 1)
+                )
+            all_outcomes[label] = round(sum(outcome_groups[label]) / 10, 1)
+
+        return {
+            "result": dict(deciles=outcome_groups, all=all_outcomes)
+        }

policyengine/economic_impact/winners_and_losers/by_wealth_decile/by_wealth_decile.py

@@ -0,0 +1,55 @@
+from policyengine.economic_impact.base_metric_calculator import BaseMetricCalculator
+from policyengine_uk import Microsimulation
+from microdf import MicroDataFrame, MicroSeries
+import numpy as np
+
+class ByWealthDecile(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_income = MicroSeries(
+            self.baseline.calculate("household_net_income"), weights=self.baseline.calculate("household_weight")
+        )
+        reform_income = MicroSeries(
+            self.reformed.calculate("household_net_income"), weights=baseline_income.weights
+        )
+        people = MicroSeries(
+            self.baseline.calculate("household_count_people"), weights=baseline_income.weights
+        )
+        decile = MicroSeries(self.baseline.calculate("household_wealth_decile")).values
+        absolute_change = (reform_income - baseline_income).values
+        capped_baseline_income = np.maximum(baseline_income.values, 1)
+        capped_reform_income = (
+            np.maximum(reform_income.values, 1) + absolute_change
+        )
+        income_change = (
+            capped_reform_income - capped_baseline_income
+        ) / capped_baseline_income
+
+        outcome_groups = {}
+        all_outcomes = {}
+        BOUNDS = [-np.inf, -0.05, -1e-3, 1e-3, 0.05, np.inf]
+        LABELS = [
+            "Lose more than 5%",
+            "Lose less than 5%",
+            "No change",
+            "Gain less than 5%",
+            "Gain more than 5%",
+        ]
+        for lower, upper, label in zip(BOUNDS[:-1], BOUNDS[1:], LABELS):
+            outcome_groups[label] = []
+            for i in range(1, 11):
+                in_decile = decile == i
+                in_group = (income_change > lower) & (income_change <= upper)
+                in_both = in_decile & in_group
+                outcome_groups[label].append(
+                    round(float(people[in_both].sum() / people[in_decile].sum()) * 100, 1)
+                )
+            all_outcomes[label] = round(sum(outcome_groups[label]) / 10, 1)
+
+        return {
+            "result": dict(deciles=outcome_groups, all=all_outcomes)
+        }