中国碳排放权交易试点政策的创新溢出效应——基于生产网络的视角

The Innovation Spillover Effect of China’s Carbon Emissions Trading Pilot Policy:Evidence from Production Networks

本文依据生产网络理论,构建理论模型论证了碳排放权交易试点政策的直接创新效应及创新网络溢出效应。在此基础上,基于地级市四位码行业层面创新数据、区域间投入产出数据与全国税收调查数据,构造双重差分模型与三重差分模型实证检验了碳排放权交易试点政策的创新溢出效应。结果表明,碳排放权交易试点政策显著促进了试点区域内规制行业创新水平,且在多种稳健性检验后结论依然成立。基于地区间投入产出关系对该政策创新溢出效应的传导路径进行了进一步分析,发现政策对相对上游行业的创新产生了负向影响,但显著促进了下游行业的创新。机制检验表明,这一生产端冲击引发的创新溢出主要通过产成品价格和生产率传导实现,且将议价能力强、与下游行业关联紧密的行业纳入全国碳排放权交易政策试点更有助于发挥政策的创新溢出效应。在“双碳”背景下,本文为评估减排政策的创新效应提供了更为深入的证据,对未来稳步推进全国统一的碳市场建设具有一定参考价值。

How to limit greenhouse gas emissions has become a global issue that affects the fate of China and the entire mankind,among which the promotion of nationwide carbon emissions trading has become an important policy tool to achieve “carbon peaking and carbon neutral.” In 2013,China launched a pilot carbon emissions trading program in eight regions.The existing studies have not yet reached a consensus on the impact of pilot policies on the innovation of regulated enterprises or industries,and only a few studies have conducted an in-depth analysis of the transmission effect of their innovation.Based on this,this study constructs a model to empirically analyze the direct innovation effect and innovation network spillover effect of the pilot policy of carbon emissions trading based on the production network theory.Theoretically,this study is based on the technological progress model of Acemoglu et al.(2012).We introduce the constraints of carbon trading and the production network mechanism to analyze the decision problem of intermediate goods inputs and innovation inputs of representative regulated firms and their upstream and downstream firms.Further,we examine the impact of the pilot policy on the level of the innovation output of representative firms in the regulated industry and their upstream and downstream representative firms.In the empirical evidence,the baseline regressions use city-industry data from 2012 to 2016 to identify the innovation effects of policies.First,the direct effect of the policy on innovation is quantified using the DID model with the pilot region regulated industries as the experimental group and the non-pilot region regulated industries as the control group.Second,the innovation spillover effect of the policy is quantified using the non-regulated industries in the pilot region as the experimental group and the non-regulated industries in the non-pilot region as the control group.In the robustness test,we minimize the distance between the estimated coefficients and reality through a parallel trend test,sample selectivity argument,exclusion of contemporaneous policies,discussion of stable unit treatment value assumption,triple difference method,and instrumental variables method(ventilation coefficient and historical carbon emissions).On this basis,this study quantifies the degree of upstream and downstream inter-industry linkages based on 2012 inter-regional input-output data and constructs a network transmission model and mechanism test.Further,we analyze the innovation effect of industry linkage heterogeneity and cross-region pilot.Based on the comprehensive theoretical model and empirical evidence,this study draws the following conclusions.(1) Carbon trading policies can promote innovation in regulated industries,and this innovation promotion effect can be transmitted through production networks.The network transmission effect lags behind the direct effect,but the network transmission effect is stronger than the direct promotion effect.(2) By constructing the upstream and downstream weights of regulated industries,it is found that the positive impact of carbon trading policy on innovation in downstream industries is stronger but has a negative impact on upstream industries.In the mechanism test,it is verified that there is a production network relationship between innovations,and the price increase and efficiency improvement of upstream firms drive downstream innovations.(3) Further study finds that the innovation effect is stronger in cross-regional carbon trading markets,and the innovation spillover effect triggered by regulated industries with higher industry linkages and stronger bargaining power is stronger.This study puts forward three suggestions.First,when promoting the pilot project of carbon emission trading rights,it is necessary to fully consider the spillover and diffusion effects caused by the policy transmission through the production network.Second,a unified national carbon emission trading market should be steadily promoted to form a more rational and balanced carbon market to bring more reasonable arbitrage space and economic incentives for innovative enterprises.Third,establish and improve relevant supporting policies to further eliminate non-economic factors that impede the free flow of factors across regions.