Zero out fuel spending for non-fuel households

changelog_entry.yaml

@@ -0,0 +1,4 @@
+- bump: patch
+  changes:
+    fixed:
+    - Zero out fuel spending for households without fuel consumption

docs/imputations.md

@@ -106,6 +106,8 @@ LCFS 2-week diaries undercount fuel purchasers (58%) compared to actual vehicle
 
 4. **At FRS imputation time**: Compute `has_fuel_consumption` directly from `num_vehicles` (already calibrated to NTS targets)
 
+5. **Zero non-fuel households**: After imputation, set `petrol_spending` and `diesel_spending` to zero for households where `has_fuel_consumption = 0`
+
 This ensures fuel duty incidence aligns with actual vehicle ownership (~70% of households = 78% vehicles × 90% ICE) rather than LCFS diary randomness.
 
 ---

policyengine_uk_data/datasets/imputations/consumption.py

@@ -344,6 +344,12 @@ def impute_consumption(dataset: UKSingleYearDataset) -> UKSingleYearDataset:
     for column in output_df.columns:
         dataset.household[column] = output_df[column].values
 
+    # Zero out fuel spending for households without fuel consumption
+    # This ensures only ICE vehicle owners contribute to fuel duty
+    no_fuel = has_fuel_consumption == 0
+    dataset.household["petrol_spending"][no_fuel] = 0
+    dataset.household["diesel_spending"][no_fuel] = 0
+
     dataset.validate()
 
     return dataset