Allocation equality of battery replacement subsidy for electric buses: Evidence from provinces and cities in China

With the global uptake of Electric Buses (EBs), a number of power batteries are nearing end-of-life, straining local government finances and causing service suspensions, particularly in less developed regions. China introduced the world's first targeted subsidy policy for replacing retired EB batteries in 2025, leaving the implementation pathways and effects unknown. This study employs support vector machine, Weibull distribution and multi-scenario simulation to reveal the spatiotemporal distribution pattern of retired EB batteries. Using the Gini coefficient, the impact of subsidy levels and local fiscal contribution ratios on allocation equality is quantitatively assessed. Based on the historical EB sales data and power battery information from 2009 to 2022, a representative case study of China is conducted, covering 31 mainland provinces and 337 cities. The results show that: (i) Cumulative retired EB battery packs are projected to reach 0.40–0.44 million during 2025–2030; (ii) The average annual local government replacement subsidy is estimated to be 327.52–362.90 million CNY, with an overall Gini coefficient of 0.30–0.39 indicating reasonable fairness; (iii) Variations in subsidy amounts and cost-sharing ratios exert a non-linear impact on overall fairness, though an optimization range exists for enhancement. This research will promote sustainable industry development and regional coordination strategies for the EB industry.