Abstract: Enterprise green technology innovation serves as a critical pathway through which policy empowerment influences carbon emission reduction and stable growth. By endogenizing the green technology innovation process within an NK-E-DSGE model and simultaneously incorporating policy instruments such as “carbon reduction loan,” carbon taxes, and green R&D subsidies, this study simulates the individual and synergistic effects of fiscal and financial policy tools based on the calibration and estimation of Chinese quarterly macroeconomic data. The simulation results indicate that: First, regarding the effectiveness of individual policy instruments, carbon tax policy demonstrates a triple effect of fostering green technology innovation, reducing carbon emissions, and promoting long-term stable growth, proving more comprehensive compared to other policy tools. Second, in terms of policy interaction effects, the implementation of “carbon reduction loan” enhances the carbon reduction effect of carbon taxes, strengthens the output-boosting effects of government environmental investment expenditures and end-of-pipe reduction subsidies, and amplifies the green technology innovation inducement effect of green R&D subsidies. Third, with respect to policy combinations, the mix of “carbon reduction loans” and carbon taxes is more advantageous for achieving both carbon reduction and stable growth. Under both the “carbon reduction-oriented” and “growth-oriented” policy evaluation frameworks, the combination of “carbon reduction loans” and carbon taxes, when coordinated with a “tax and fee reduction” type of proactive fiscal policy, yields higher evaluation scores than when coordinated with an expansion of green fiscal expenditures. This conclusion holds even when further combined with loose monetary policy. Fourth, the government can further optimize the macroeconomic regulation effects of policy combinations by adjusting the carbon tax rate and the interest reduction coefficient of “carbon reduction loan”, thereby achieving a “Pareto improvement” in social welfare.

Key words: “carbon reduction loan”, fiscal policy, green technology innovation, carbon emission reduction effect, economic stabilization effect