Environmental protection taxes and green productivity: Evidence from listed companies in China

Enforcing an environmental protection tax is a pivotal institutional measure for addressing environmental and climate change challenges and marking a substantial advancement in ecological development. This study aims to explore the influence of environmental protection taxes on the "green" productivity of the manufacturing industry through an analysis of Chinese listed companies. Initially, the Dynamic Slacks-Based Measure (DSBM) method is employed to estimate the "green" production efficiency levels of 175 listed companies in China from 2016 to 2020. Subsequently, by aligning pollution tax standards issued by local governments and relevant environmental protection departments with microlevel data from the CSMAR database, wind database, listed company annual reports, and social responsibility reports, the sample was refined to 833 data points. Using the implementation of the environmental protection tax policy in 2018 as a natural experiment, a Difference-in-Differences (DID) model is applied for empirical testing. The empirical results reveal a counterintuitive negative correlation between the environmental protection tax and the "green" productivity of companies, contradicting the predictions of the Porter hypothesis. This suggests that stringent environmental regulations hinder the development of green technologies. The adverse impact of environmental protection taxes on "green" productivity is attributed to heightened environmental legitimacy pressures and increasing environmental uncertainty risks companies face. Further exploratory analysis indicated that the digital economy and green finance have a positive moderating effect, significantly mitigating the negative impact of environmental protection taxes on companies' overall "green" productivity. Consequently, dynamically optimizing environmental tax policies is imperative to alleviate companies' environmental legitimacy pressures and uncertainty risks. Additionally, capitalizing on the opportunities the digital economy presents and leveraging green finance policies have emerged as effective strategies for realizing the Porter effect of environmental protection taxes.