Methodology note
Fund EV scrappage grants: note
Models fund ev scrappage grants in 2028-29. The estimate is illustrative and excludes wider package interactions.
Central fiscal result
+£4.0bn - Net fiscal impact in 2028-29
Low case: +£2.0bn. High case: +£8.0bn. Positive numbers are fiscal costs or borrowing pressure. Negative numbers are Exchequer savings or receipts.
Scenario and baseline
- Models fund ev scrappage grants by 2028-29.
- Baseline is current policy or published departmental plans.
- Central case uses published party or official anchors where available.
- Wider manifesto interactions are excluded unless stated.
Affected population
- Affected units are people, firms, households or providers depending on policy.
- Direct exposure follows the manifesto or government target group.
- Indirect exposure includes suppliers, workers, consumers and taxpayers.
- Weakest counts are widened in the low and high cases.
Gross impact
- Published anchor or scenario central is +£4.0bn in 2028-29.
- Gross costs or receipts are adjusted for behaviour and delivery risk.
- Tax, benefit or procurement offsets are separated in the fiscal build-up.
- The range is deliberately wider where implementation detail is thin.
Fiscal build-up, central case
- Gross programme or delivery cost: +£4.6bn
- Tax and receipt offsets: -£0.3bn
- Administration and evaluation: +£0.1bn
- Behavioural and pass-through effects: -£0.4bn
Central net impact: +£4.0bn in 2028-29.
Behaviour and pass-through
- Low case assumes stronger delivery or receipts than central.
- Central case applies moderate behavioural leakage and pass-through.
- High case allows weaker delivery, larger take-up or higher costs.
- Output effects follow incidence, capacity and investment channels.
- Distributional gains do not automatically imply GDP gains.
Phasing
- 2026-27: +£0.4bn. Phased implementation and take-up.
- 2027-28: +£2.2bn. Phased implementation and take-up.
- 2028-29: +£4.0bn. Phased implementation and take-up.
- 2029-30: +£4.0bn. Phased implementation and take-up.
Main source groups
- Davis and Kilian, "Estimating the Effect of a Gasoline Tax on Carbon Emissions" (American Economic Journal: Economic Policy, 2011): Fuel taxes can reduce gasoline consumption and emissions, with distributional and behavioural effects; relevant to motoring and aviation tax measures.
- Institute for Fiscal Studies, "Green Party manifesto: a reaction" (2024): Used to define the pledge wording, policy scope and implementation scenario being modelled.
- Local Government Association, "Green Party manifesto summary" (2024): Used to define the pledge wording, policy scope and implementation scenario being modelled.
- Parry and Small, "Does Britain or the United States Have the Right Gasoline Tax?" (Journal of Urban Economics, 2005): Efficient motoring taxes should reflect congestion, accidents, pollution and revenue needs; relevant to EV mileage and fuel duties.
- Climate Change Committee, "Progress in reducing emissions" (2025): CCC reports persistent delivery gaps across buildings, transport, power and land-use decarbonisation; supports the need for investment while cautioning on deliverability.
- HM Treasury, "Spending Review 2025" (2025): Spending Review settlements set the counterfactual for departmental capital and resource budgets; used to separate new spending from existing baselines.
- Green Party of England and Wales, "Manifesto for a Fairer, Greener Country" (2024): The manifesto defines the tax, spending, climate, housing and public-service proposals modelled here; used to define the scenario, not as an official costing.