Technology spillover and incremental cost effects of carbon transfers on optimal carbon quotas in supply chains.

A fair and effective allocation of carbon quotas is crucial for China to achieve its "Double Carbon" goals and the effective operation of its carbon trading market. By constructing a differential game model, this study explored the effects of the technology spillovers and incremental costs of carbon transfers on the allocation of carbon quotas under centralised and decentralised decision-making scenarios with the purpose of maximizing social welfare. This paper proposes a cost-sharing contract to coordinate a supply chain for the loss of social welfare under decentralised decision-making. The results show that the effects of spillovers and incremental costs on carbon quota allocation depend upon the enterprises' abatement costs. The suppliers' carbon quotas are negatively correlated with the spillover effects. The incremental cost effects will be more pronounced for suppliers when their abatement costs are high and they could obtain more carbon quotas accordingly. When the manufacturer's abatement costs are low (high), its carbon quotas decrease (increase) with the spillover effects but increase (decrease) with the incremental costs. The cost-sharing contract achieves Pareto improvements based on improved social welfare and increased carbon quotas for both the manufacturer and supplier. Given the effects of carbon transfer on enterprises with different abatement costs, this paper can provide the government with a reference for designing an allocation mechanism for carbon quotas. [Display omitted] [ABSTRACT FROM AUTHOR]