2.1. Literature Review
Abundant environmental data are a prerequisite for improving the efficiency of pollution prevention and control, and the disclosure of environmental information is an important way to safeguard the environmental rights of the public [
14]. In order to win the blue sky battle and achieve green development, China encourages various forms of environmental information disclosure. The disclosure of environmental data is mainly driven by official efforts, and data collection and disclosure are carried out through official government organizations. Currently, research related to environmental data disclosure mainly includes the evaluation of official environmental information disclosure policies and the exploration of the impact of environmental information disclosure on pollution emissions, green innovation, economic development, and other aspects.
Environmental information disclosure policies were implemented earlier in European and American countries and achieved good results in pollution control; studies have found that environmental information disclosure policies improve environmental performance by disclosing corporate environmental violations and exposing companies to direct penalties and indirect economic losses [
9,
15]. The low cost of environmental crime in China leads to the failure of environmental information disclosure policy in the financial market [
16], but it can enhance residents’ pro-environment behavior [
17]. Strong public opinion can make up for policy deficiencies, to a certain extent, and put pressure on local governments to improve environmental quality [
18].
Environmental information disclosure brings limited punishment to heavily polluting enterprises, but after a period of time, it can promote the transformation of urban industrial structure and the progress of environmental protection technology, and significantly reduce urban pollutant emissions. The emissions reduction effect is sustainable and will be enhanced with the enhancement of regional pollution laws and environmental regulation [
14]. Environmental information disclosure can improve public awareness of environmental conditions and scientificize intuition. For example, the public can easily obtain accurate air quality information through applications such as Mobile Weather. Open environmental information can improve the public’s environmental participation and the government’s environmental law enforcement efforts to ultimately reduce urban pollution emissions, and for non-resource-dependent cities, this emissions reduction effect is more significant [
19]. The opening of environmental information not only reduces the emissions of local pollutants, but also has a spatial radiation effect, which helps to improve the ability of surrounding areas to clean up pollutants [
11]. Pan et al., 2022 also confirmed that environmental information openness promotes the formation of environmental governance by the government, enterprises, and the public, increases the government’s environmental concern, stimulates the public’s motivation to monitor environmental protection, promotes enterprise restructuring, and reduces regional pollution emissions. Moreover, the effect of emissions reduction is more obvious in regions where officials have stronger awareness of avoiding environmental punishment and less financial pressure [
20].
Environmental information disclosure can effectively alleviate environmental information asymmetry between central and local governments [
21], change officials’ motivation for environmental protection, and urge local officials to carry out substantive environmental governance; local governments’ motivation for environmental governance will eventually increase corporate pressure for environmental protection, prompting firms to significantly increase their investment in environmental protection. This effect is stronger for firms whose executives have experience in public office [
22]. Environmental information disclosure motivates local governments to enhance enterprises’ green innovation motivation through political pressure channels and law enforcement channels, and the effect is long term [
23]. Enterprises’ enthusiasm for environmental innovation will eventually improve the level of urban green innovation, and the higher the level of information disclosure, the more obvious the effect of urban green innovation [
24]. Enterprises with a stronger ecological concept are also more willing to publish their own environmental information, and the voluntary disclosure of environmental information has a positive impact on enterprise innovation investment and can enhance the technological innovation ability of enterprises [
25]. After the disclosure of environmental information, the enthusiasm of green innovation in industries with high environmental risks is significantly improved, especially in non-patent-intensive enterprises and state-owned enterprises, and the synergistic effect of public opinion and environmental law enforcement can further strengthen the green innovation effect of environmental information disclosure. The disclosure of environmental information also provides more environmental protection materials for new media, a free media environment encourages heavily polluting enterprises to actively innovate green technology to meet the requirements of stakeholders, and pollution charges and penalties brought by regulation will also force enterprises to improve green technology innovation [
26].
Environmental information disclosure can also significantly improve the urban total factor energy efficiency by improving the regional research and development levels and innovation ability, promoting regional energy conservation and emissions reduction technology levels, and replacing polluting industries with clean industries [
27]. Improved energy efficiency can lead to increased green economic efficiency in cities, with each unit increase in government environmental information disclosure increasing the green total factor productivity by 20%, and the effect is nonlinear, with the increase being greater as the level of environmental information disclosure increases [
28]. The disclosure of China’s environmental information will also significantly affect foreign direct investment, promote the exit of polluting foreign-invested enterprises that have entered the market, and increase the investment of clean enterprises, leading to an ecological transformation of the foreign investment structure [
29]. Environmental information disclosure can also play the role of resource allocation of green finance, stimulate green orientation in the capital market, and improve green investment [
30]. Most of the above literature treats environmental information disclosure as an event and analyzes the social impact of environmental information disclosure by conducting quasi-natural experiments. This method is able to measure the impact of environmental data disclosure on pollutant emissions reduction and green innovation in a broad direction but is prone to some biases in accurately estimating the relationship between the level of environmental data disclosure and air pollution, green innovation, etc. [
20].
The essence of environmental information disclosure is the openness of environmental data, which is one of the results of digitalization construction. Current research on the impact of digitization and intelligence on environmental information openness and environmental pollution is also relatively abundant. Shi et al., 2018 empirically tested whether smart cities reduce urban environmental pollution by changing urban development patterns through modern information technology [
31]. Technology optimization and industrial upgrading brought about by digital transformation significantly reduced the power consumption intensity, thus reducing energy consumption and pollution [
32]. Xiao et al., 2023 believe that digitalization can affect enterprise carbon performance through green technology innovation, and this relationship is a U-shaped curve [
33]. It can be seen that digitalization has an important impact on environmental pollution, although the impact of digitalization and intelligence on the environment is broader and deeper than the impact of data disclosure on the environment. However, environmental data disclosure and digitalization development have a close relationship. Digitalization-related research can still be used as an indirect reference for the study of the relationship between environmental data disclosure and pollution emissions.
After the implementation of the Environmental Information Disclosure Measures (Trial) in 2008, the Institute of Public and Environmental Affairs (IPE) and the Natural Resources Defense Council (NRDC) jointly published the Report on the Disclosure of Regulatory Information on Pollution Sources in Key Cities, which is a scientific evaluation of the status of the disclosure of regulatory information on pollution sources in key cities, starting in 2008 and continuing annually until 2018 with good continuity. After the Ministry of Environment and Ecology of the People’s Republic of China issued a new method for environmental information disclosure in 2013, the IPE and NRDC, after repeated discussions and argumentation, decided to revise the calculation standard of the Pollution Information Transparency Index (PITI), which has been in use for 4 years, and formed the PITI under the new standard. The new standard is more complete, reasonable, feasible, and scientific, so PITI can effectively measure the level of environmental data disclosure at the city level. This paper carries out a quantitative study of the level of environmental data disclosure on pollution emissions using six indexes from 2013 to 2018, and carries out an in-depth discussion of the impact mechanism to improve the existing research on environmental information disclosure on urban pollution emissions.
2.2. Research Hypothesis
In the era of digital economy, data and information play an important role in the strategic adjustment, production, and operation of enterprises. The disclosure of environmental data increases the cost of environmental violations for enterprises and will have an impact on enterprise productivity and pollution weight, thus affecting regional pollutant emissions.
Referring to Kovak et al. [
34], the urban production function is set as the Cobb–Douglas production function:
Q represents the output;
L and
K, respectively, represent the input of labor and capital;
A is the comprehensive technical level;
α is the elastic coefficient of labor output; and
β is the elastic coefficient of capital output. Referring to Bai et al. [
35], the production function driven by digitalization is
,
,
A0 is the initial technical level,
θA denotes the propensity for technological progress due to data openness,
θA > 0, and
E is the level of environmental data disclosure. The resulting production function incorporating data openness is shown in Equation (2):
By-products will inevitably be produced along with the desired products and, referring to Stokey and Sheng [
36,
37], the pollution function is written as
;
z is the pollution factor per unit output. Digital infrastructure, information level, etc., are the basis for open data application, and these prerequisite foundations will likewise improve enterprise productivity. Drawing on the approach of Bai et al. [
35], pollution weight is linked to the level of data openness,
,
z0 is the initial pollution value before the opening of environmental data, and
θz is the change tendency of urban pollution weight caused by the opening of data. The application of enterprise data can lead to the improvement in enterprise production efficiency, to the adoption of the existing literature hypothesis [
35], and to
θz > 0 when the enterprise production efficiency increases.
In a perfectly competitive market, the product price at competitive equilibrium is
p, the fixed cost is
C, the product cost is the unit variable cost
b, the initial pollution cost is
Cw0, and the propensity to change the marginal abatement cost is
θw. Theoretically, when the level of environmental data disclosure exceeds a certain threshold, the total cost of urban pollution increases sharply due to the increased regulatory capacity and the limitation of pollution treatment level; the cost of pollution treatment is
Cw = Cw0 +
θw ×
W. Through the above setting, the total target profit function and constraint conditions of enterprises are obtained as follows:
Pollution emissions under optimal selection are obtained:
The first-order and second-order derivatives of Equation (4) can be obtained as shown in (5) and (6), respectively:
Before the opening level of environmental data reaches a critical value, the overall quality of data is not high, which renders it difficult to substantially improve the government and public’s ability to regulate enterprises’ environmental violations. On the contrary, it may induce enterprises’ speculative psychology. Before the opening level of environmental data can substantively affect enterprises’ fines for violating the law, enterprises will try their best to use the time window to expand production, resulting in an increase in pollution emissions. The mathematical representation is that Equation (6) is less than 0. Pollution emissions increase with the level of environmental data disclosure when E is small. When the level of environmental data disclosure reaches the threshold, environmental data can greatly enhance the ability of the public and the government to supervise the emissions of enterprises, and the cost of illegal emissions of enterprises increases sharply. At this time, pollutant emissions will decrease with the continuous improvement in the level of environmental data disclosure.
When the level of environmental data disclosure is low, the public cannot accurately grasp the current environmental situation, and the awareness of environmental protection participation will be weak. The ambiguity of environmental information also makes it more difficult for the government to enforce environmental laws and weaken the environmental supervision by higher government to lower government, resulting in a weaker overall environmental regulation in society. With the development of digitalization and intelligence, the level of environmental data disclosure will continue to improve, and the ability of environmental supervision will be strengthened. Therefore, when the level of environmental data disclosure is low, enterprises will expand their production in order to obtain more profits, which makes urban pollutant emissions increase. When the level of environmental openness is high and the cost of environmental violations increases, enterprises’ emissions behavior will gradually be restrained, and at this time, the early environmental protection investment also begins to have an effect, and urban pollutant emissions will show a downward trend. Thus, Hypothesis 1 is proposed.
Hypothesis 1. There is an inverted U-shaped curve relationship between environmental data disclosure and urban pollutant emissions.
Pollutants are unavoidable by-products of the production process, but the use of green technologies to improve resource utilization efficiency can reduce pollutant emissions per unit of product [
38], mitigate the environmental hazards caused by economic activities, and enhance the environmental and economic benefits of enterprises [
39]. Green technology innovation has become a key tool to reduce pollutant emissions. A high level of environmental data disclosure alleviates the environmental information gap between the central and local governments, enterprises, and the public [
24]; facilitates the environmental supervision of the higher-level governments and the public; and increases the environmental pollution costs of the lower-level governments and enterprises. In order to cope with increasingly severe environmental constraints, enterprises have been motivated to enhance green technology innovation. Porter’s hypothesis also supports this conclusion from the perspective of environmental regulation. In order to encourage green development, the government will increase investment in scientific research [
40] and provide incentives, such as subsidies, to enterprises that pay attention to ecological protection, actively carry out green technology innovation, and reduce pollutant emissions. Subsidies can have a significant positive impact on enterprises’ green innovation by easing financial constraints [
41]. Under the “carrot and stick” incentive policy, high-quality environmental data disclosure will inevitably force high-polluting enterprises to actively carry out green technology innovation to reduce energy consumption and pollution to cope with more stringent and precise environmental regulations in the future. However, when the level of environmental data disclosure is low, it is difficult for environmental regulation to drive enterprises to carry out innovation activities. Enterprises often choose to bear the cost of environmental violations and the pressure of environmental violations “crowding out” the ability and willingness of enterprises to carry out innovation [
42]. At this time, external stakeholders cannot supervise enterprises’ green innovation activities through public low-quality environmental data, and the agency costs faced by green innovation are aggravated, which may hinder enterprises’ green innovation [
43].
Nowadays, society is more concerned about environmental issues, and social public opinion and social financial support are more inclined to favor green and environmental protection enterprises. As a medium, environmental data disclosure can change the financing constraints of enterprises by transmitting the urban environment information, environmental management, and environmental awareness of local enterprises to lenders and creditors. With a low level of environmental data disclosure, it is difficult to convey effective information, which enhances the probability of green financial mismatch, distorts the financing cost constraint of green innovation, and reduces the level of green innovation of enterprises; a high level of environmental information disclosure reduces the risk concerns of lending institutions and the financing cost of environmental protection enterprises. As a result, environmental protection enterprises will be more likely to receive green financial support and more resource rationing, and will possess increased funds for green innovation [
44]. Green innovation will eventually become an important driver of clean economic growth and reduced pollution emissions [
45]; hence, Hypothesis 2 was produced.
Hypothesis 2. The level of environmental data disclosure influences urban pollution emissions through green innovation.
Environmental pollution can inhibit the inflow of regional talent and promote the outflow of population and labor [
46]. Lower levels of environmental data disclosure cannot effectively improve the government’s environmental monitoring capacity, and low levels of environmental regulation and poor environmental quality can increase public depression and reduce the public’s life satisfaction [
47], contributing to the outflow of urban migrants; this effect is more pronounced for well-educated people [
48]. An increased level of environmental data disclosure will enhance the sense of urgency of green development in cities, and cities will gradually retire high-energy-consuming and high-polluting enterprises and introduce clean industries that are mostly knowledge- and technology-intensive. Thus, urban industrial restructuring brings changes in the composition of urban human capital. More employment opportunities and a better livable environment will attract more senior talents, which will continuously improve the overall cultural literacy of the city and enhance the overall social responsibility and environmental awareness of the city [
49]. The improvement in social participation awareness and environmental protection concepts will enhance public expectations of urban environmental quality, making urban pollution emissions face greater constraints. Local governments will increase environmental supervision to meet public environmental demands, and public supervision also provides a public basis for the government’s precise environmental governance. The cooperation between the public and the government will increase the cost of environmental violations by enterprises and force them to reduce pollutant emissions as much as possible. At the same time, talent-gathering facilitates enterprises’ quicker acquisition of suitable R&D and management talents, improvement in enterprise operation efficiency, and reduction in enterprise costs. The talent aggregation effect satisfies the diverse talent needs of enterprises and cities, improves the green transformation ability of cities and enterprises, and is conducive to reducing urban pollutant emissions from the source [
50]. Therefore, Hypothesis 3 is proposed.
Hypothesis 3. The level of environmental data disclosure affects urban pollutant emissions by changing the regional talent aggregation effect.
Environmental data disclosure increases urban environmental constraints, and in the era of digital economy, the phenomena of urban industrial restructuring and industrial agglomeration are intensifying. The environmental pressure brought by environmental data disclosure motivates cities to use various digital technologies to amplify the positive effects of industrial agglomeration and improve resource utilization efficiency as much as possible [
51,
52]. Many traditional heavy-industry cities with unreasonable industrial structures continue to optimize industrial layouts, strengthen industrial collaborative agglomeration, increase urban clean investment, promote the exit of pollution-oriented enterprises from the market [
29], and improve the level of green technology innovation through the introduction and development of high-tech industry and a knowledge-intensive service industry to enhance the urban green total factor productivity [
53]. Therefore, although urban environmental pollution will be aggravated due to concentrated pollution emissions and low green production efficiency at the beginning of the industrial adjustment and industrial agglomeration [
54], the improvement in urban green total factor productivity in the later period is conducive to reducing urban pollution emissions. Therefore, Hypothesis 4 is proposed.
Hypothesis 4. Environmental data opening level reduces urban pollutant emissions by improving regional green total factor productivity.