1. Introduction
Digital technologies have been embedded in every economic and social activity today; nearly all industries now use digital technology to promote production and business reform. A subsequent development is the overturning of traditional business models, which in turn reshapes management, production, and supply chains, leading to new consumption systems able to create manufacturing and service themselves. Notably, digital technology changes market demand; hence, residents can enjoy the convenience of digitalization when consuming new products and services. Improvements in supply efficiency and the resulting changes of market demand lead to changes in the industrial structure. The digital economy is therefore believed to lead to the eventual upgrading of the industrial structure, accelerating the process of industrialization and improving the level of economic service.
China is the world’s largest industrial economy. However, following the international financial crisis in 2008 it has been faced with the demand for industrial structure upgrading. On one hand, the rise of factor costs has reduced the cost advantage of product production, which requires supply side industrial structure upgrading. On the other hand, increases in resident incomes have increased the market demand for services, which requires industrial structure upgrading. In addition, the realization of carbon neutrality requires the industrial structure to shift to high-value-added economic activities in order to ease and extend the value chain of products [
1,
2]. The digital economy provides an impetus to upgrade the industrial structure. As a country with this advantage, China urgently needs to use digital technology to upgrade said industrial structure. According to the White Paper on Global Digital Economy Development Report released by the China Academy of Information and Communications Technology, the digital economy grew from USD 0.32 trillion to USD 6.03 trillion dollars from 2005 to 2020, accounting for 14.2–38.6%, respectively, of the country’s Gross Domestic Product (GDP), with its growth rate reaching 9.6% in 2020. Furthermore, the penetration rates of the digital economy of the primary, secondary, and tertiary industries are 8.9%, 21%, and 40.7%, respectively. Therefore, China’s promotion of industrial structure upgrading through the digital economy is deeply pivotal for other emerging and developing countries.
The digital economy is a new and crucial force in revolutionizing scientific and technological assets, modernizing the economic system, and providing sustainable economic and environmental development, all of which China needs to promote industrial structure reform. This can be achieved in three ways. First, digital technologies and the digital economy are primary drivers of the scientific and technological revolution, which is crucial in enhancing market competition in these areas [
3,
4]. Second, the digital economy promotes the construction of a modern economic system. With high innovation, strong penetration, and wide coverage, the digital economy takes data as its key production factor, and is therefore both a new economic growth point and a fulcrum that optimizes and upgrades traditional industries, thereby becoming an important engine in constructing a new economic system [
5,
6]. Finally, in addition to the supply side, the digital economy changes the structure of demand. For example, residents are more willing to enjoy intelligent services of industrial products, with virtual reality technology providing various new entertainment items.
Several studies have discussed the role of information technology or the digital economy in changing basic industrial process and organizational activities, improving the efficiency of resource allocation, and providing industrial structure optimization [
7,
8]. Other studies have examined how the digital economy affects the structural changes in primary, secondary, and tertiary industry. The existing literature mainly examines the impact of the digital economy on productivity in manufacturing, services, or other specific industries, often using a single digital economy index [
9,
10]. For example, studies have found that the digital economy promotes green and innovative development in the industrial economy [
11,
12]. Other studies discuss the spatial spillover effects of the digital economy on the industrial structure [
6]. The digital economy and industrial structure both have important spatial spillover characteristics, and ignoring these may greatly reduce the policy implications of research conclusions.
Digital technology is a general-purpose technology leading the fourth industrial revolution, and is having a profound impact on industrial development and its structure. However, the relationship between technology and industry is complex. Does the digital economy lead the industrial structure to change towards the goal of social development? For example, it is arguably better able to meet the service needs of residents and increase the industrial competitiveness of developing countries. Therefore, it is necessary to reveal the laws and characteristics of the digital economy and its contribution to upgrading of the industrial structure. This study empirically investigates the impact of the digital economy on the industrial structure in China in order to discover the new path and theoretical basis of the transformation and upgrading of the industrial structure and sustainable economic development. First, in contrast with existing research, which primarily uses internet penetration, digitalization, and digital finance to stand in for the digital economy, this study constructs a comprehensive index of digital economic development from four dimensions, namely, digital industrialization, industrial digitalization, digital finance, and digital infrastructure, drawing on data from 237 prefecture-level cities in China from 2010–2019. Next, this study’s research perspective focuses on both the impact of the digital economy on the upgrading of the industrial structure and on the mechanisms of technological progress and human capital upgrading. Finally, this research adopts the spatial econometric model to explore the spillover effect of the digital economy on the advancement and servitization of the industrial structure by decomposing its direct and indirect effects.
The remainder of the paper is organized as follows:
Section 2 provides a brief literature review;
Section 3 explains the study’s theoretical analysis and research hypothesis;
Section 4 presents the methodology used, including model setting, data description, and data collection; and
Section 5 outlines and discusses the empirical results. The final section,
Section 6, concludes and discusses policy implications.
2. Review of Related Literature
Previous studies have posited that the digital economy mainly refers to the information economy or network economy, which are respectively driven by information and communication technologies (ICT) [
13]. ICT has led to relatively revolutionary developments in both the economic and societal arenas, and the network economy and digital economy both represent new economic formats gradually formed with the widespread adoption of ICT. In 1996, Tapscott first put forward the concept of the digital economy; Kim defined the digital economy as a new aspect of the economy beyond the existing traditional economic imagination, and research into the digital economy has received more and more attention [
14,
15]. The Organization for Economic Co-operation and Development (OECD) and the US Census Bureau and Telecommunication Technology Committee (TTC) in Japan have defined the concept of digital economy as well. Several scholars have studied the measurement of digital economy indicators in different dimensions. For example, Barefoot et al. [
16] constructed a comprehensive measure of the digital economy using its contribution to GDP. Bukht and Heeks [
17] developed a definition estimated from three scopes of relevance: the digital sector, its output based on digital goods and services, and the digitalized economy.
With the rapid development of the digital economy, scholars have begun to focus on exploring the economic and social dividends of the digital economy in an attempt to reveal the positive impact of digital economy on economic growth, social progress, sustainable development, and other aspects. Awad and Albaity [
18] revealed that, in addition to the direct contribution of ICT to growth, ICT indirectly promotes economic growth through investment, openness, and education. Other studies have disclosed that digital technology provides a means to help the economy achieve sustainable development [
19,
20] as well as that digital facilities increase energy demand and pose additional challenges to sustainability [
21]. The impact of ICT adoption on the economic performance of enterprises is the most widely discussed topic. Most studies have affirmed the economic benefits of ICT investment, while others studies suggest that a productivity paradox exists [
22,
23]. Although certain results remain controversial, most researchers believe that the digital economy promotes industrial development and economic efficiency, which is in turn reflected in one or more aspects of financial, environmental, and social performance [
24].
On the adjustment of industrial structure, two main dimensions arise, namely, the internal (i.e., industrial structural optimization) and the external characteristics (i.e., industrial structural upgrading). The main method reflecting industrial structure optimization considers the deviation in the output value and employment structure of each industry along with each industry’s difference in economic status [
25]. As digitalization improves the efficiency of information transmission and promotes the opening of the regional economy [
26], it improves the efficiency of resource allocation and promotes the optimization of industrial structure. According to Clark’s law, industrial structure upgrading refers to the process of improving the industrial structure from a low level to a high one, including the advancement and servitization of industrial structure.
Studies have measured industrial structure advancement by the hierarchical coefficient of industrial structure [
27,
28]. Such studies involve the evolution of industrial proportional relations and the improvement of labor productivity [
29], or simply use the ratio of added value to GDP in secondary industry and tertiary industry [
30]. Digital technology dramatically affects the industrial structure of major industrialized countries, upgrading their industrial structure to the tertiary industry level. Studies have used the ratio of the added value in the service sector to the added value in the manufacturing sector as an indicator of this industrial structure upgrading [
27,
31,
32].
Industrial structure is closely related to total factor productivity, energy efficiency, economic security, and green sustainable development [
33,
34,
35], which is why many studies empirically examine the economic, environmental, and social effects of industrial structure. For example, Luan et al. [
36] found that industrial structure adjustment can act as a positive measure to reduce energy intensity in China. The modernization of industrial structure is the premise of a country’s industrial security and international competitiveness [
37], and developing countries have great demand for industrial structure upgrading. Meanwhile, scholars have studied the path of optimizing and upgrading the industrial structure from different dimensions, such as the effectiveness of progress in capital-embodied technology, green innovation, and digital technologies in upgrading industrial structures [
38,
39]. Moreover, environmental regulation, ecological compensation, and low-carbon policies have been shown to have a positive effect on upgrading of the industrial structure [
25,
40,
41].
Considering the wide application of digital technology in various industries, studies have investigated the relationship between digital technologies and industrial structure. Many studies have investigated the influence of digital technologies on specific industries. Park and Heo [
9] comprehensively examined the impacts of ICT convergence on value chain changes in the electricity industry, focusing on changes in the value chain. Del et al. [
10] revealed that ICT plays a positive role in improving the performance and overall financial stability of the banking industry. Other studies have explored the digital economy and industrial structure. For example, Kim and Park [
42] examined the crucial role of the ICT industry in the global network based on Korean industry, showing the significance of emphasizing the outflow of ICT industrial knowledge to promote information with respect to other non-ICT industries. Li [
43] found that technical change and internet development greatly reduced labor costs and led to industrial transformation in China. Su et al. [
6] studied the process of upgrading the industrial structure by developing the digital economy, and explored the relationship between scientific and technological innovation and industrial structure upgrading.
5. Empirical Results and Discussion
5.1. Estimated Results of Baseline Regression
To make the results more comparable, columns (1) and (3) list the results of the panel model under city fixed effect, while columns (2) and (4) show the results of the panel model under time and city fixed effects. According to
Table 3, the results of the Hausman test are significant at the 5% and 1% level, while the likelihood ratio (LR) test results are all significant at the 1% level, which means that the results can be regressed with clustering robust standard deviation under time and city fixed effects.
Empirical results show that the direct effect of digital economy development on the advancement of industrial structure is significantly positive at the 5% level, while the direct effect on the servitization of the industrial structure is significant at the 1% level. This indicates that the development of the digital economy can promote the three levels of industry (primary, secondary, and tertiary), enhancing the advancement and servitization of the industrial structure and thereby proving the first hypothesis. Two reasons can explain these findings: first, the integration of digital technologies occurs mainly in secondary and tertiary industry; for example, in 2020, digital industrialization and industrial digitization accounted for 7.3% and 31.2% of GDP, respectively, with the ratio even reaching 40.7% for the service industry. Second, the existence of many new models and forms of business emerging in the consumption and service sectors breaks space and time limitations, promoting the development of a new service industry and the servitization of digital industry.
Moreover, the regression results of other factors basically meet the theoretical expectations. With economic development (lnGDP) and investment (lnInvestment) having positive effects on the upgrading of the industrial structure, the newly increased economic activity in Chinese cities mainly comes from advanced or service-oriented industries. Foreign direct investment (lnFDI) can stimulate enhancement of servitization in the industrial structure. However, higher deposits from residents (lnFinance) leads to reduced spending, which hinders the development of tertiary industry. The impact of urbanization on industrial structure remains uncertain.
5.2. Estimated Results of the Mediation Effect Model
Table 4 reports the estimation results of the mediation effect model using technological progress (
lnRD) and human capital upgrading (
lnHR) as mediation variables. Columns (1) to (3) use technological progress as the mediation variable, while columns (4) to (6) use human capital upgrading. Columns (1) and (4) show that the effect coefficients of the digital economy on technological progress (0.109) and human capital upgrading (0.165) are significantly positive, indicating that the digital economy can promote technological progress and enhance human capital levels.
It is evident from columns (2) and (5) that the regression coefficients for the relationship between technological progress, human capital level, and advancement of the industrial structure are all significantly positive at the 1% level, at 0.087 and 0.086, respectively. These results pass the Sobel test, indicating that the digital economy can positively upgrade the industrial structure by promoting technological progress and human capital levels. In light of these results, we can see that the indirect effects of the digital economy on industrial structure advancement through technological progress and human capital level are significantly positive, at 0.003 and 0.004, respectively.
Columns (3) and (6) show that the impact coefficients of technological progress and human capital level between the servitization of industrial structure are all significantly positive at the 1% level, at 0.152 and 0.151, respectively. These results pass the Sobel test as well, with T-values of 2.021 and 2.422, respectively. This indicates that the digital economy can positively promote the development of the industrial structure servitization by promoting technological progress and human capital level. Hence, the servitization of the industrial structure is indirectly enhanced by the digital economy, with values of 0.002 and 0.004, respectively.
The two possible reasons for the above-mentioned results are as follows. First, the digital economy can allow entrepreneurs to more conveniently obtain innovative resources, greatly improving innovation efficiency [
6]. Digital technology can be applied to new industries, such as new chips, basic software, intelligent hardware, etc., to promote industrial modernization [
39]. The digital economy can integrate with traditional industries, promote the intelligent development of traditional industries, and push enterprises to manufacture products for consumers and provide full life-cycle services. Moreover, as digitalization needs highly educated and skilled labor, human capital improves through increased sharing of knowledge among platforms and easier access to knowledge, improving management and technological progress and promoting the advancement of the industrial structure. Nevertheless, the digital economy may lead to wage polarization and income inequality, which decreases its potential to increase industrial efficiency and impedes upgrading of the industrial structure [
59].
5.3. Estimated Results of the Spatial Durbin Model
5.3.1. Spatial Correlation Test
In this study, Moran’s I index is used to evaluate the spatial correlation of industrial structure in various Chinese regions.
Table 5 shows that the global Moran’s I index values for the advancement of industrial structure (
lnIndustry_gh), the servitization of industrial structure (
lnIndustry_ser), and digital economy development (
lnDigital) from 2011–2019 are significantly positive at the 1% level. The null hypothesis of no spatial autocorrelation is significant; therefore, China’s industrial structure and digital economy development have significant spatial autocorrelation, and conducting spatial econometric analysis is appropriate.
5.3.2. Model Selection Test
Table 6 shows the diagnostic test results for the spatial econometric model under the 0–1 rook spatial weight matrix (
W1) and the inverse distance geographic matrix (
W2). For advancement of the industrial structure, the value of the Lagrange multiplier (LM) test, robust Lagrange multiplier (LM) test, and Wald test are all positive. Therefore, the choice of the spatial Durbin model is reasonable. Meanwhile, for the servitization of the industrial structure, we found that the values for the robust LM (lag) test are insignificant. Hence, we report the results for the SAR model instead.
5.3.3. Spatial Effect Estimation Results
Table 7 reports the estimation results of the spatial econometric models. Columns (1) and (2) report the estimation results of the digital economy on advancement of the industrial structure based on SAR under
W1 and
W2. The regression coefficients all are positive, with 0.011 at the 5% level. Columns (3) and (4) show the results of servitization of the industrial structure based on SDM under
W1 and
W2. Evidently, the coefficients are all positive, at 0.140 and 0.105 at the 1% level. These results are consistent with the estimated coefficients for the basic models in
Table 3, showing the robustness of our spatial econometric models. This indicates that the development of the digital economy can significantly upgrade the industrial structure.
To further analyze the effect of digital economy development on regional industrial structure, this paper deconstructs the impact of the digital economy on industrial structure into both direct and spillover effects under
W1 and
W2 based on SDM for advancement of the industrial structure and SAR for servitization of the industrial structure, shown in
Table 8. Looking at the results of columns (1) and (2), the coefficients of the direct effect of the digital economy on the advancement of the industrial structure are significantly positive at 0.010. However, the coefficients of the indirect effect are all negative, at −0.017 and −0.156; despite its under
W1, it not significant under
W2. It is evident that while the development of the digital economy can upgrade the industrial structure of local regions, it impedes upgrading of the industrial structure in neighboring regions. In columns (3) and (4), the coefficients of the direct and indirect effect based on SAR under
W1 and
W2 are all significantly positive at the 1% level. This indicates that the development of the digital economy can enhance the level of industrial structure servitization in both local and neighboring regions.
In essence, the development of the digital economy promotes the advancement and servitization of the industrial structure in local regions and enhances the servitization of the industrial structure of neighboring ones. However, it hinders upgrading of the industrial structure in neighboring regions. This can be explained by the following reasons. First, the development of the digital economy can promote the development of technological progress and human capital, which upgrades the industrial structure and enhances the servitization of the industrial structure in local regions. Next, the digital economy can strengthen the advantages of the local industrial structure, which promotes further upgrading within the local industrial structure from labor-intensive and capital-intensive industries to technology-intensive and green-intensive ones. Hence, it impedes upgrading of the industrial structure of neighboring regions. Third, the development of digital servitization gives rise to new business models, which both enriches the variety of tertiary industries and expands the scope of service, bringing an increasing level of tertiary industry to both local and neighboring areas.
5.4. Estimated Results of Robustness Analysis
The 2SLS method is a feasible method for solving problems related to endogenous explanatory variables [
60]. As the lagged terms of the independent variables satisfy the exogeneity and correlation conditions, they are usually selected as instrumental variables. In this study, we chose the first-order lag term of the development of digital economy as the instrumental variable. In order to avoid measurement deviation in the digital economy indicators, we adopted broadband infrastructure as a proxy variable for the digital economy. According to Zhou et al. [
61], broadband is a modern infrastructure serving the digital economy. In 2014, China officially selected pilot cities to implement China’s broadband strategy and increase their construction of broadband infrastructure. This paper defines these pilot cities as the treatment group, other non-pilot cities as the control group, and uses the difference-in-differences (DID) design to evaluate the causal relationship between the digital economy and industrial structure.
Finally, from the perspective of the three major industries, the upgrading of industrial structure means that the proportion of primary industry continues to decline, the proportion of secondary industry first rises then subsequently falls, and the proportion of tertiary industry continues to rise. To avoid the influence of deviation in the index measures on our estimation results, we refer to Zheng [
27] in replacing the calculation method for the industrial structure in our robustness test. This study calculates the industrial structure, expressed as
, where
qi represents the ratio of output value of different industry to the regional GDP,
.
Table 9 presents the results of the linear regressions. Columns (1) and (3) report the results of the advancement and servitization of industrial structure under 2SLS, showing that the coefficients are all significantly positive, at 0.240 and 0.265 at the 1% level. Columns (2) and (4) report the results of DID estimation, showing that the Broadband City strategy significantly upgrades the industrial structure and promotes servitization at the 1% level, reconfirming the reliability of our findings. Columns (5) and (6) report the results of OLS without control variables, while columns (7) and (8) show the results of OLS with control variables. As the results of the Hausman and LR tests are all significant at the 1% level, this study adopts the Ordinary Least Squares (OLS) with clustering robust standard deviation under time and individual dual fixed effects in columns (6) and (8). It is clear that the coefficients of digital economy on upgrading of the industrial structure are significantly positive, at 0.018 and 0.021 at the 1% level. This indicates the robustness of positive effect of digital economy on upgrading industrial structure.
Moreover,
Table 10 reports the results of the robustness test of the mediation effect with technological progress and human capital, showing that the coefficients of the mediation effects are at 0.001 and 0.001 at the 1% level of significance. The robustness results of the spatial effect are shown in
Table 11, showing that the direct effects are significant at 0.012 and 0.013 under
W1 and
W2. However, the indirect effects are significantly negative at −0.008 and −0.193, respectively. Therefore, these results indicate that while the development of the digital economy can upgrade the industrial structure in local regions by prompting technological progress and human capital, it impedes the same development in neighboring regions. This matches the results in
Table 4 and
Table 8, demonstrating the robustness of the mediation effect and spatial effect between the digital economy and upgrading of the industrial structure.
6. Conclusions and Policy Recommendations
The challenge of climate change has brought external requirements to the upgrading of the industrial structure [
62], while digitalization has brought internal impetus to the same. This study constructs a comprehensive measurement system for the digital economy and then investigates the impact of the digital economy on the industrial structure based on panel data from 237 prefectural-level cities in China from 2011–2019. It adopts panel regression to empirically analyze the direct impact of the digital economy on upgrading the industrial structure, and uses a mediation model to prove the mediation effect of technological progress and human capital upgrading. Furthermore, this study reveals the spatial spillover effect of the digital economy on the advancement and servitization of the industrial structure based on the SDM and SAR models.
Our main research conclusions are as follows. First, development of the digital economy can promote the transformation and adjustment of industrial structure in local regions from a low-level state to a high-level one. Robustness tests, such as the method of calculating the digital economy and industrial structure, that is, the 2SLS method, show that this finding is robust. Second, the digital economy can promote upgrading of the urban industrial structure through the intermediary mechanisms of promoting technological progress and human capital upgrading. Finally, there exists a spatial spillover effect between the digital economy and industrial structure upgrading. Specifically, development of the digital economy can promote the servitization of the industrial structure in a region and its surrounding areas. Although the digital economy can promote the advancement of the industrial structure in this region, however, it hinders advancement of the industrial structure in surrounding areas.
Based on these findings, the following policy recommendations are proposed. All regions can take advantage of the digital technology dividend to promote industrial upgrading and service orientation. With the declining international demand for manufacturing and the country’s rising internal production costs, China’s industrial structure faces an urgent need for transformation and upgrading. In addition to improving digital infrastructure, developing countries need to formulate industrial policies for the digital economy in order to help industries realize advanced and service-oriented upgrading through digital transformation. The effectiveness of the industrial policy for development of the digital economy deserves attention, as it is the key to determining a region’s competitive advantage in the opportunity period of global industrial structure adjustment [
63,
64]. Moreover, it is important for enterprises to improve the knowledge, experience, and skills of their human resources and more effectively match their current pool with their organizational needs through development of the digital economy in order to improve production efficiency, management efficiency, and strategic development. Finally, the government should pay attention to the spatial spillover effect of the digital economy on industrial structure upgrading and strengthen spatial cooperation in industrial upgrading [
65]. In the era of the digital economy, regional competition and cooperation between industries are more important. The government should formulate regional coordination policies for digital economic development in order to promote cooperation in industrial development.
This paper presents a preliminary discussion about the relationship between the digital economy and the industrial structure; however, there are deficiencies in this study and more remains to be done. First, it would be better to use an integrated index for both the digital economy and industry in order to reveal the effect of development of the digital economy on the industrial structure. However, we were only able to construct a comprehensive index of the digital economy, as we lacked official statistics for an integrated index. Second, while this paper has tried to investigate the impact of the digital economy on the industrial structure, our results do not reflect the effects on the internal structure of manufacturing. The upgrading of the internal structure of manufacturing in the digital economy era is one of the topics that must be studied in the future. In addition, studies in specific regions may be helpful in providing more targeted policy implications.