关键词: 碳税, 资金约束, 风险, 碳减排技术研发

Abstract: In response to the environmental problems we are currently facing, governments around the world have taken a series of measures to reduce carbon emissions. The implementation of carbon tax policy significantly affects the production and operational activities of enterprises, prompting them to transition towards more low-carbon and environmentally friendly production methods. In this context, more and more enterprises have chosen to increase their investment in Research and Development (R&D) for carbon emission reduction technologies. However, not all of these enterprises have sufficient funds to effectively advance the R&D of such technologies. In practice, Small and Medium-sized Enterprises (SME) with financial constraints often have financing demands for carbon emission reduction technology R&D projects. It is worth noting that there are risks of failure in the R&D of carbon emission reduction technologies, which weakens SME motivation for R&D and affects their R&D and financing decisions. Therefore, it is necessary to conduct an in-depth study on whether enterprises will choose to carry out carbon emission reduction technology R&D activities by means of financing under the carbon tax policy. How do the risks associated with R&D of carbon emission reduction technologies impact the collaboration between SME and financial institutions in the realm of carbon finance? Based on the aforementioned considerations, this paper constructs a game model between a capital-constrained enterprise and a financial institution, compares and analyzes the optimal decision-making of both the baseline model and the carbon emission reduction technology R&D financing model. The aim is to derive an optimal R&D financing strategy for the supply chain that accounts for the risks associated with R&D failure.
   The main conclusions of this paper are as follows: Firstly, when the success rate of R&D is low, if the enterprise does not have bankruptcy risk, both product sales and profits for the enterprise and the financial institution will consistently exceed those in the baseline model. However, if the enterprise does face bankruptcy risk, the baseline model effectively mitigates the risks for both parties, ensuring that their profits remain intact. Secondly, the carbon tax rate is also an important factor affecting the choice of financing strategy. A higher tax rate increases the bankruptcy risk for enterprises, prompting those with limited liability capacity to adopt a more aggressive production and R&D strategy. Finally, it is important to note that the carbon emission reduction technology R&D financing model is not universally beneficial for the environment. The effectiveness of emission reduction technology R&D in promoting environmental protection is contingent upon specific conditions being met regarding carbon emissions per unit of product and the success rate of R&D.
   This paper establishes a theoretical foundation for the government to formulate an appropriate carbon tax rate, while promoting the collaboration between enterprises and financial institutions to mitigate emissions. Additionally, it examines the boundary conditions necessary for the effective carbon finance cooperation between these entities, offering both theoretical and practical support for SME carbon financial financing activities and their regulation in the context of carbon tax. However, this paper acknowledges certain limitations that need further exploration in future research. Firstly, it focuses solely on a supply chain comprised of a single enterprise and a single financial institution. In reality, supply chains typically involve multiple participants, and the decision-making processes of these members are influenced by a variety of factors, making their decision-making challenges more complex. Secondly, this study assumes that the financing interest rate set by financial institutions is fixed. Future research could incorporate financial institutions into the decision-making process to investigate the financing strategies of enterprises when the interest rate is endogenous.

Key words: carbon tax, fund constraint, risk, carbon reduction technology R&D