1. Introduction
Advancements in such internet technologies as big data, artificial intelligence, and blockchain have propelled the digital economy and economic growth [
1,
2]. According to the World Internet Development Report (2018), released during the 5th World Internet Conference, China ranks second in the World Internet Index, just behind the United States. China attaches great importance to developing the digital economy, and the government has issued many related policy documents. Under these policy incentives, China’s digital economy had grown from RMB 11 trillion at the beginning of the 13th Five-Year Plan to RMB 45.5 trillion yuan in 2021 (data comes from the National Bureau of Statistics of China). New digital technology and the Internet have drastically reduced search, entry, transportation, and reproduction costs, unleashing enormous potentials for enhancing economic efficiency. There is no doubt that the digital economy impacts every aspect of our lives [
3]. If we consider the digital economy as encompassing all economic activities that use or are facilitated by digitized data, then it is essentially the entire economy.
Meanwhile, global environmental problems have gradually been exposed. In recent years, air pollution represented by haze pollution has occurred frequently and affected a wide area, seriously endangering public health. According to the latest “2021 China Ecological and Environmental Status Bulletin” released in May 2022, 35.7% of 339 prefecture-level and above cities still exceed the standard for ambient air quality. The average number of days exceeding the standard in 339 cities was 12.5% of days analyzed. Among them, the number of days with PM2.5, O3, PM10, NO2, and CO as the primary pollutants accounted for 39.7% of the total number of days exceeding the standard. High concentration of PM2.5 is one of the important reasons for the formation of haze weather and the reduction of ambient air quality. PM2.5 has been reduced for six consecutive years since the start of the 13th Five-Year Plan period, from 46 micrograms per cubic meter to 30 micrograms per cubic meter. Even so, the current level of air pollution in China is still more than three times higher than the guideline value identified by the World Health Organization (average annual concentration of no more than 10 micrograms per cubic meter). Therefore, alleviating and solving the problem of PM2.5 pollution remains the top priority in China’s environmental protection battle.
The ecological environment problem is fundamentally a problem of development mode and life style. The digital economy is a significant means to optimize and upgrade the economic structure and achieve high-quality economic development in the new era, thereby changing the way of production and life, which can improve the above problems. Chinese government departments have introduced a series of policies to promote the deeper integration of the digital economy and traditional industries, improve the quality and efficiency of social production, and guide the green economic transformation. For example, it is clearly proposed to accelerate the digital transformation of production mode in the latest “14th Five-Year Plan for Green Industrial Development” released in November 2021. Specifically, industrial Internet, big data, 5G, and other next-generation information technologies should be employed to improve energy, resource, and environmental management, deepen the digital application of production and manufacturing processes, and enable green manufacturing. As can be seen, China’s green development, pollution prevention, and control efforts depend heavily on the digital economy. Therefore, it is sensible to further examine whether or not the digital economy could potentially have reduction effects on pollution emissions.
Currently, the relationship between the digital economy and environmental pollution has gradually drawn the attention of academics, but the literature is still inconclusive with mixed results. On the one hand, some academics have conducted in-depth research on the relationship between the digital economy and environmental pollution, and the conclusions mainly include the following three aspects. First, most scholars believe that the digital economy brings environmental purification and reduces pollution. High resource allocation efficiency of the digital economy [
4,
5] and the use of digital auxiliary platforms with less waste of resources [
6,
7,
8], second-hand goods platforms, and product recycling [
9] are all beneficial for reducing pollution emissions. In addition, Li et al. studied the micro-energy network architecture of enterprise zero carbon emission, and demonstrated that this architecture can greatly reduce the emission of air pollutants [
10]. Lee et al. also verified the carbon reduction effect of the digital economy in the transportation sector [
11]. Second, some studies found that the digital economy exacerbates environmental pollution. Sui and Rejeski pointed out that each potential positive impact of the digital economy is coupled with a potentially overwhelming negative impact as well [
12]. For example, moving business online can reduce waste such as printed catalogues, retail space, and transportation requirements, but we have to manufacture more energy-intensive computers instead. Meanwhile, information and communications technology (ICT) with a large amount of electricity and carbon-intensive materials as intermediate production also has limited impacts on carbon reduction [
13,
14,
15,
16]. Third, some studies argue that there is a nonlinear relationship between the digital economy and environmental pollution, and the related environmental impacts are also characterized by heterogeneity. For example, Xu et al. found that there is a reverse and complex spatio-temporal evolution of the digital economy and environmental pollution in Chinese cities [
17]. Lee et al. focused on the relationship between digital financial inclusion and carbon neutrality and found that the marginal impact of digital financial inclusion on carbon intensity first decreases and then increases [
18]. Regarding the heterogeneous impact of the digital economy on the environment, it mainly includes regional heterogeneity [
19], the differences between resource-based and non-resource-based cities [
20]. On the other hand, some literature also explores the specific mechanism of how the digital economy affects the environment, and mainly includes mediating effects and moderating effects. Specifically, the relevant mediating effects are primarily that the digital economy can influence economic growth, financial development, and industrial structure upgrading, thereby reducing carbon emissions [
21]. Additionally, technological innovation and human capital [
22], energy efficiency [
23], and resource allocation [
24] also play mediating roles. The moderating effect mainly includes R&D investment [
25] and environmental regulation [
26].
It is worth noting that only a few scholars have focused on the connection between the digital economy and PM
2.5, and the majority of the aforementioned literature uses carbon emissions to represent the level of environmental pollution. For example, Qi et al. found that the digital economy has a stronger improvement effect on the SO
2 concentration than its improvement effect on the PM
2.5 and NO
2 concentrations [
27]. Che and Wang also verified the haze reduction effect brought by the development of China’s digital economy and analyzed the heterogeneity characteristics of the haze reduction effect [
20]. However, the above studies either have too broad research objectives, considering many pollutants, or do not fully consider the relevant mediating effects, moderating effects, and other influencing mechanisms.
In short, although extensive research has been carried out in the relevant field, there exists no study paying attention to the comprehensive effect of the digital economy on PM2.5 and its influencing mechanism. Compared to prior research, this paper advances the literature as follows: (1) Previous studies generally focused on the environmental effects of the digital economy, but few studies focused on the analysis of PM2.5 emissions. This paper integrates the digital economy and PM2.5 emissions into a unified research framework, which is consistent with China’s development idea of supporting the deep integration of the digital economy and ecological civilization construction. (2) Cities are playing an ever-more-important role in intelligent innovation and pollution avoidance as digital and smart cities emerge. However, previous studies lack empirical evidence at the city level in China. This paper uses panel data from 285 prefecture-level cities in China from 2005 to 2018 to explore the impact of digital economy development on PM2.5, and our sample helps fill the aforementioned gap. (3) This paper investigates the influence mechanism of the digital economy on PM2.5 emissions, including the mediating effect of technological innovation and the moderating effect of environmental information disclosure. Our research will provide more precise development guidance for harnessing the digital economy to reduce PM2.5 pollution.
The rest of this paper is arranged as follows:
Section 2 sorts out the theory development.
Section 3 states the econometric model, variables, data, and its source.
Section 4 presents the empirical analysis and test results.
Section 5 analyzes further discussion.
Section 6 shows the conclusions and implications of this paper.
5. Discussion
As a new form of economic and social development, the digital economy profoundly affects every aspect of society. In order to supplement existing theoretical and empirical studies, this paper investigates the impact of the digital economy on PM
2.5 pollution and its influencing mechanism in detail. After a series of tests, the research results show that the development of the digital economy can effectively reduce PM
2.5, which is consistent with the conclusion of scholars who support the digital economy’s development [
65].
The mediating effect test shows that technological innovation is a significant mediator affecting the impact of the digital economy on PM2.5 pollution. The development of the digital economy has dramatically shortened the time and space distances, and integrated resources for industries. Then, it provides a favorable research environment and achievement transformation channels for technological innovation, such as green technology innovation and low-carbon technology innovation. As a result, technological innovation will promote the research and development of cleaner production technology and low-carbon environmental protection products, thereby enhancing the ability to manage pollution and lower PM2.5 emissions.
The regression results of the moderating effect model and the corresponding robustness test show that environmental information disclosure can strengthen the reduction effect of the digital economy on PM
2.5 emissions. The development of the digital economy has dramatically promoted the dissemination of information, and the disclosure of environmental information will raise public concern about environmental pollution and governance. On the one hand, more environmental awareness among the populace will strengthen the social supervision of the government and corporate behavior. Studies have shown that public participation can complement the role of government in environmental governance and pollution reduction [
66]. On the other hand, by accessing the disclosed information, the public understands the severity of climate change and air pollution [
67].
Through the above analysis and discussion, this paper has obtained the reduction effect of the digital economy on PM
2.5 pollution and its influence mechanism, and the three hypotheses have been verified. However, there are some limitations to this study. The impact of the digital economy on technological innovation is a long-term process, and the mediating effect of technological innovation should be discussed further. Meanwhile, some scholars found that the information industry has many embodied pollution emissions through input-output studies, which require comprehensive carbon management strategies [
68]. In addition, the scope of urban environmental information disclosure needs to be further improved.
6. Conclusions and Policy Implications
Existing studies are insufficient on the impact of the digital economy on PM2.5 emissions. Therefore, using the panel data of 285 cities from 2005 to 2018, this paper empirically tests the relationship between the digital economy and PM2.5, the mediating role of technological innovation, and the moderating effect of environmental information disclosure. The findings are as follows. (1) The development of the digital economy can significantly reduce PM2.5. (2) Technological innovation plays a partial mediating role in the influence of the digital economy on PM2.5 pollution. (3) Environmental information disclosure can strengthen the PM2.5 reduction effects of the digital economy. The higher the extent of environmental information disclosure, the more pronounced the reduction effect of the digital economy on PM2.5.
This study has the following policy implications. Firstly, the government should enhance digital infrastructure construction and increase investment in digitization. More importantly, the government should strengthen the application of the digital economy in pollution prevention and control. Society should improve the governance system of digital and guide enterprises to carry out digital and green transformation. Secondly, local governments and enterprises should be encouraged to make full use of the research environment provided by the digital economy and strengthen knowledge and technology sharing to carry out green technological innovation and research on environmentally friendly products. Finally, in the age of the digital economy, the government should improve the construction of environmental information disclosure network platforms, encourage more cities to disclose ecological information voluntarily, and mobilize the public’s enthusiasm to participate in environmental governance.
In conclusion, although this study provides new insights into the influence of the digital economy on PM2.5 emissions and provides practical implications, some limitations might deserve further investigation. Considering the important role of enterprises in the digital economy and pollution reduction, this paper only uses cities as a study sample, unable to reveal the influencing mechanism at the enterprises level. Future research can attempt to examine the environmental effects of enterprise digital transformation and carry out analysis on specific cases. Moreover, the existence of other mediating and moderating factors also deserves further study.