Guiding policy of green technology innovation and green consumption considering positive externality of products

• Green products are divided into self-interested products and altruistic products. • Guiding policy of GTI and green consumption should consider positive externality. • An evolutionary game model of government, enterprises and consumers is built. • Government only needs implement subsidy policy for self-interested products. • Government needs to implement both subsidy and carbon tax for altruistic products. Green technology innovation (GTI) is the key path to promote green development and achieve China’s carbon peaking and carbon neutrality goals. Insufficient innovation motivation of enterprises and depressed market demand are still important reasons restricting GTI. The positive externalities of green products have significant impact on market demand and then the innovation motivation of enterprises. The optimized guiding policy should be proposed based on the consideration of products’ positive externalities. This paper divides green products into self-interested and altruistic. Then a tripartite evolutionary game model of government, enterprises and consumers is built. The impact of policy related parameters on evolutionary stable strategy (ESS) is analyzed, including subsidy and its distribution coefficient, carbon tax and its distribution coefficient. The results show that government can promote green behavior of enterprises and consumers through just implementing subsidy policies for self-interested products. While for altruistic products, government needs to implement subsidy and carbon tax policies simultaneously.