Negative externality in the exploitation and utilization of environmental resources cannot be solved by market alone. As a form of Pigouvian taxes, pollution charge is an important way to internalize the external cost of a firm. Chinese government promulgated “Interim Measures for the Collection of Pollution Charge” in 1982, which formally established the pollution charge system in China. It has had a profound influence on Chinese environmental governance in more than 30 years. (Guo et al., 2019). In order to further standardize the pollution charges, “Environmental Tax Law of China” was implemented in 2018 to change pollution charges into environmental tax officially. According to the polluter pays principle (PPP), firms are the major object of the environmental tax, which may burden them with more operating cost. So we come up with the following questions naturally: Will environmental tax affect the competitiveness of firms, and can it produce strong Porter effect? If so, what is the path? To answer these two questions is of great significance to evaluate the implementation effect of environmental tax and guide the reform to the next stage.
Although the impact of the levy of environmental tax on macroeconomic development and firms’ behavior as micro-players in China is still unknown due to lack of relevant data and short execution time, what is known is that the legislation of environmental tax follows the principle of smooth transition of “charge to tax” that no significant change in the levy object, scope and calculation standard between environmental protection tax and pollution charge (Wang et al., 2019). The biggest change from pollution charge to environmental tax is that the legal status of pollution charge is relatively low, which is easy to form levy and management obstacles (Wang et al., 2003). The inherent legal authority of environmental tax further strengthens the tax rigidity, which will significantly improve the intensity of levy (Xu, 2015; Huang and Li, 2018). Based on the fact that there is no big difference between environmental tax and pollution charge, we can evaluate the implementation effect of Chinese environmental tax through the policy of pollution charge (Lu et al., 2019), and discuss whether environmental tax can produce strong Porter effect and how, so as to provide policy reference for the reform of environmental tax.
In order to test Porter hypothesis better, Jaffe and Palmer (1997) divided it into three forms. The first one is weak Porter hypothesis, which implies that strict environmental regulation policy can stimulate innovation in firms, but its influence on innovation that increases firm competitiveness is uncertain. Scholars have basically reached a consensus that the weak Porter hypothesis is tenable. Calel and Dechezleprêtre (2016) found that regulated firms have higher innovation investment than unregulated firms based on European environmental regulation policy research. Empirical studies by Manderson and Kneller (2012), Nesta et al. (2014), Song et al. (2019) and Shang et al. (2021) also found that environmental regulation and innovation are positively correlated; The second is the narrow Porter hypothesis, which indicates that flexible regulatory policies incentivize firms greater to innovate than stiff ones. López-Gamero et al. (2010) found that flexible environmental regulation is conducive to encourage firms to develop new processes and products while stiff regulatory policies are not. Jaffe et al. (2002), Brouhle et al. (2013), Ambec et al. (2013) and Sun et al. (2021) also prove that compared with direct regulation based on command and control such as environmental standards and emission limits, market-based and flexible regulation greater motivate firms to innovate; The third is the strong Porter hypothesis, which means that innovation in firms provoked by stronger environmental regulation can completely offset any additional costs from environment protection and improve firms’ competitiveness. The conclusions of existing researches on strong Porter hypothesis are controversial, and scholars often conduct research from the perspective of productivity. Dension (2010) found that the reason for the productivity of the United States decreased by 16% during 1972-1975 is the intensified environmental regulation. Cagatay and Mihci (2006) and Hering and Poncet (2014) also get a similar conclusion that environmental regulation have adverse effect on competitiveness. However, Berman and Bui (2001) found that the productivity growth of the petroleum smelting industry in Los Angeles, where strict air quality control has been implemented, is much higher than that in other parts of the United States. Other literature such as, Hamamoto (2006), Peuckert (2014), Wang et al. (2019), found evidence that environmental regulation improves productivity as well.
From the literature above, we can see that the major controversy existing in three forms of Porter hypothesis is the strong Porter hypothesis. We infer that there are four important reasons for the inconsistency. Firstly, Porter and Van der linde (1995) believe that strict and properly designed environmental regulation can stimulate innovation and partially or completely offset the adverse effect of compliance cost. Therefore, the prerequisite in the establishment of the strong Porter hypothesis is strict and properly designed environmental regulation. Although what is "strict and properly designed" environmental regulation is still inconclusive, studies have confirmed that there is an inflexibility in command-control environmental regulation, and inflexible regulation even inhibits the environmental innovation behavior in firms (Montero, 2002; Reequate and Unold, 2003). The comprehensive environmental regulation indicators used in literature often include inflexible environmental regulation, which may make the results inaccurate for they do not comply the prerequisite of the strong Porter hypothesis. Secondly, environmental regulation indicators are often endogenous in economic research (Copeland and Taylor, 2004): Environmental regulation variables and dependent variables are reciprocal causation, or environmental regulation variables correlated with omitted variables and other unobservable factors leads to endogenous problems, which will affect the accuracy of the conclusion greatly. Thirdly, the existing literature does not make a clear distinction between environmental innovation and non-environmental innovation. Researchers often consider the overall innovation in firms, but environmental regulation promotes green-biased innovation the most (Requate and Unold, 2003; Acemoglu, 2012), and the effects of the two types of innovation on firms competitiveness are obviously different, misleading the results. Fourth, most of the researches measure the firm competitiveness by their total factor productivity (TFP). In fact, the firm competitiveness is also affected by many factors in addition to TFP, including demand factors, factor endowments and corporate image, etc. For example, the environmental protection behavior of a firm may also enhance competitiveness through providing environment-friendly products and establishing a green corporate social image. Kammerer (2008) found that some consumers are more willing to pay for green products with high prices when the products reduce pollution and have added value.
We attempt to alleviate the four problems mentioned above. Taking Chinese A-share listed companies that disclosed environmental R&D from 2008 to 2017 as samples, we focus on the environmental tax which is the most typical market-oriented environmental regulation in China[1]. We measure firm competitiveness by firm performance to test whether environmental tax can produce strong Porter effect. Furthermore, instrumental variable is introduced to reduce the adverse effect of endogeneity, and a series of robustness tests are conducted to prove that there is a stable causal relationship between environmental tax and firm performance. In the end, this paper establishes a mediating effect model to analyse the mechanism from environmental tax to firm competitiveness according to two paths of Porter hypothesis -- innovation compensation and first-mover advantage. Figure 1 shows the empirical research framework of this paper.
This paper may have the following marginal contributions. First of all, the existing studies do not explain the mechanism of environmental regulation affecting firm competitiveness clearly. On the one hand, although there are relevant literature on mechanism of innovation compensation, they do not further distinguish between environmental R&D and non-environmental R&D that whose impacts are obviously different. This paper separates environmental innovation from overall innovation by collecting the corporate environmental R&D data in CSR reports, focusing on whether environmental innovation can bring innovation compensation effect. On the other hand, previous researches mainly discuss about innovation compensation but ignore the effect of first-mover advantage although Porter hypothesis contains these two core paths. On the contrary, this paper analyses both the effects of innovation compensation and first-mover advantage, providing micro evidence from China to validate strong Porter hypothesis and its mechanism. Secondly, this paper fully considers the endogenous problem resulting from reciprocal causation and omitted variables. We prove that there is a robust causal relationship between environmental tax and firm performance by introducing instrumental variables and conducting a series of robustness tests, which provides causal identification evidence for the strong Porter hypothesis. Thirdly, although a handful of literature compare different types of environmental regulation rather than only use comprehensive environmental regulation as independent variable, it is difficult to analyse the causality and mechanism of specific environmental regulation tools under this approach. For more in-depth analysis, this paper only takes the most typical market-based environmental regulation in China, environmental tax, into consideration and discusses corresponding causality relationship and influence mechanism.
This study proceeds as follows. Section 2 contains Policy background and characteristic facts. Section 3 provides the methodology and describes the data. Section 4 discusses empirical procedures and major findings. Section 5 consists of research conclusions and policy recommendations.
[1] Market based environmental regulation mainly includes environmental tax, emissions trading, subsidies and deposit return. Emission trading in China is only carried out in some areas, and the trading volume is still small while the subsidy and deposit return are lack of corresponding data.