Self-developed innovation vs. government-funded support: competitive strategies in blue carbon trading under different industry–research collaboration structures

To clarify the complex relationships among blue carbon suppliers, research institutions, and third-party institutions, which involve both industry–research cooperation and price competition in blue carbon trading, this study is based on a new biform game method. By combining the Shapley value and Nash equilibrium, a mathematical model is constructed and solved. Starting from factors such as R&D effectiveness, additional returns, and government funding, the pricing, R&D input, and investment strategies of these key actors under different industry–research structures are examined. The results show that: (1) Under external competition, when R&D effectiveness is relatively high, third-party institutions can gain advantages through selling blue carbon at a price lower than the purchasing price to maximize the overall internal benefits of their system, and improve their own returns under a reasonable allocation mechanism. (2) Improvements in R&D effectiveness can simultaneously increase the R&D effort and investment levels of members within the focal system, and indirectly reduce the R&D effort levels of institutions in the rival system, but do not change the investment strategies of blue carbon suppliers in the rival system; therefore, institutions do not need to be overly concerned about losses caused by competition. (3) The self-directed R&D mode and the government-funded mode exhibit complementary characteristics in terms of risk protection and return potential in blue carbon trading. Starting from the pricing mechanism under a competition–cooperation framework, this study provides certain implications for future research on blue carbon pricing strategies and participation modes of stakeholders under the influence of more actors’ strategies.