The R&D and sharing of emission reduction technology with uncertainty and carbon tax under inter-chain competition

This study investigates the boundaries and effects of emission reduction technology R&D and sharing in competitive supply chains considering uncertainty and carbon tax, and further explores contracts to improve technology sharing. Employing a game-theoretic approach, we construct a model involving two competing supply chains, each comprising a manufacturer and a retailer, whereby manufacturers engage in Stackelberg leadership within chains and Cournot competition between chains. The analysis encompasses scenarios of no R&D, unsuccessful R&D, successful R&D without technology sharing, and successful R&D with sharing. We find that technology R&D and sharing promote emission reductions and enhance manufacturers' profitability. Technology R&D improves the economic and environmental performance of supply chains under certain conditions, whereas technology sharing fails to improve economic performance owing to intensified double marginalization effects. Specifically, technology sharing negatively impacts retailers' profitability and consumer surplus, ultimately reducing social welfare; meanwhile, introducing revenue-sharing contracts effectively mitigates these adverse impacts, facilitating technology sharing. Furthermore, we demonstrate that carbon tax stimulates technology R&D and sharing; however, excessively high tax rates may impede economic performance, resulting in an inverted U-shaped relationship between carbon tax rates and social welfare. Optimal carbon tax rates are heavily influenced by inter-chain competition intensity and technological efficiency. This study provides novel insights by integrating inter-chain competition, technology R&D uncertainty, and carbon tax into a unified framework, thereby offering meaningful implications for policymakers and supply-chain practitioners aiming to balance emission reduction with economic efficiency.