4.1. Measurement of Development Levels of Two Regions
After obtaining the corresponding data, the development levels of the digital economy in the 30 provinces in China in 2004–2019 are calculated (see
Table A2 in the
Appendix A).
Figure 1 gives the average scores of the development levels in the 30 provinces. The development levels in Beijing and Shanghai are much higher than those in other provinces. In addition, the average scores in 11 southern provinces are greater than 0.2, while only eight northern provinces have such values. Thus, the average development levels of the digital economy in the south are higher than those in the north.
Figure 2 gives the average scores of the development levels in the nationwide, southern, and northern regions from 2004 to 2019. Overall, the average score of the national development level in the past sixteen years is relatively low, which is only 0.2778. However, developmental levels are on the rise, from an average score 0.2086 in 2004 to 0.3465 in 2019. From the regional distributions, the development level in the south is higher than that in the north, and the difference between the southern and northern regions is large. It shows that the development of the digital economy in China is concentrated in the southern region, the development in the northern region is relatively slow.
Table 3 gives the status quo of the development level, which is analyzed by regional classification of the four first-level indicators in
Table 1. In terms of digital infrastructure, the southern region has a larger score. The differences between these two regions are striking, indicating that the digital infrastructure construction level in the southern region is higher than that of the northern region.
Regarding the digital innovation ability, the southern region again has a higher score than the northern region. The southern region has strong digital innovation ability due to its advantages in capital investment, scientific research, and higher education. In addition, the southern region has invested more funding in infrastructure, communication technology transformation, and upgrading investment in recent years.
In terms of digital industry scale, the score of the southern region is much higher than that of the northern region. The digital industry chain in the southern region is becoming more complete, and the digital industry has been developing toward large-scale and intensive development. The digital economic output is much higher than that of the northern region. Finally, for digital technology application, the score of the southern region is much higher than that of the northern region, and the northern region is lower than that of the nationwide.
In general, the southern region is ahead of the northern region in all the four aspects, among which the scale of digital industry and the application of digital technology are much more advanced than the northern region.
4.3. Results of Kernel Density Estimation
Using 2005, 2012 and 2019 as the test time periods,
Figure 5 gives the estimates of density functions for the development levels of the digital economy in the whole country and two regions. In all these three figures, the distributions move to the right while the right tail of the kernel density estimation curve is long, indicating that the development levels of the digital economy in the nation and two regions have been improved in recent years. However, there are still problems regarding the low-level aggregation and uneven spatial distribution. Each of these three kernel density curves have a double peak, which suggests that the development level of digital economy in China is polarizing. The wave peaks in the southern region and whole country have the tendency of becoming shorter and wider, which indicates that the development of the digital economy in China is unbalanced. The southern provinces with high development levels will improve the development level faster, while the provinces with low development levels will improve the development level at a low rate. Therefore, the imbalance of the digital economy development between provinces is becoming more and more obvious.
As time goes on, the peak on the right side of the nationwide kernel density map gradually weakens, which indicates that the distribution of development level in the whole country may shift from a multipolar pattern to a single pattern. In the sample observation period, the wave peaks of the kernel density estimation curve in the northern region first decrease and then increase. The gap between the development levels in different northern provinces first increases and then gradually narrows.
4.4. Results of Network Analysis
According to the method in
Section 3.6, the digital economic development scores of 30 provinces from 2004 to 2019 are tested by the Granger causality test. The results show that 71 associations are identified.
Figure 6 gives the association map of China’s digital economic development network using the Gephi software. The spatial correlation is not limited to inter-provincial in the southern region or northern region, but inter-provincial in the whole country. The number of associations within the northern region or the southern region is less than the number of associations between provinces across regions, which is an unexpected result.
Moreover, the spillover effect of association is not restricted by geographical location but exists widely among different provinces. For example, Xinjiang has the largest number of related provinces, and it has spillover effects on the development of the digital economy in Beijing, Gansu, Hunan, and Shanxi. In addition, Guangdong, Hainan, Hubei, Liaoning, Ningxia, Shandong, Sichuan, Yunnan, and Inner Mongolia benefit the development of the digital economy in Xinjiang. Among these provinces, Hunan, Guangdong, Hainan, Hubei, Sichuan, and Yunnan belong to the south, and Xinjiang, Beijing, Gansu, Shanxi, Liaoning, Ningxia, Shandong, and Inner Mongolia belong to the north. Xinjiang is only adjacent to Gansu.
Figure 1 shows that the development level of the digital economy in Xinjiang is lower than these provinces except Ningxia. It is expected that Xinjiang should obtain benefits from these provinces with a high level of digital economy development. The question is why Xinjiang has spillover effects on provinces with higher digital economy levels. According to the reports of Xinjiang’s digital economy in recent five years, we find that Xinjiang has built a high-level, technologically advanced digital infrastructure connecting the world. Xinjiang has realized the docking of an optical cable system with neighboring countries such as Kazakhstan and Kyrgyzstan, and thus become an important west-facing inter-national telecommunications network hub in China. This may be the reason why Xinjiang’s digital economy development is relatively low, but it is related to many other provinces in the network.
According to the definition in
Section 3.6, the network density of China’s digital economy development is 0.082. This indicates that the inter-provincial correlation is low, and the regional cooperation of digital economy is insufficient. By collaborative development based on regional advantages and provincial advantages, the development speed of digital economy and the development level of China’s digital economy can be accelerated.
Table 4 gives the spatial network centrality of China’s digital economy development. In the south, there are 38 beneficial associations and 33 spillover associations between provinces. On the contrary, there are 33 beneficial associations and 38 spillover associations between provinces in the north. Thus, the south has more benefited effects, but the north has more spillover effects. If the southern provinces with higher levels of digital development can give full play to the spillover effect in the northern provinces in the future, the development level of digital economy in the north will be further improved.
In the south, Jiangxi, Hunan, Hubei, and Sichuan are more associated with other provinces. Their relative degree centralities are higher, which are 0.241, 0.241, 0.207 and 0.207, respectively. In the north, Xinjiang, Inner Mongolia, and Shanxi are more related to other provinces, and their relative degree centralities are 0.414, 0.310, and 0.207, respectively. Among the 30 provinces, the relative degree centralities of Beijing, Shanghai, and Guangdong, which rank top three in digital economy development level, are relatively low. This shows that provinces with a high level of digital economic development have strong spillover potential.
Regarding the betweenness centrality, two southern provinces, Hunan and Chongqing, and two northern provinces, Inner Mongolia and Xinjiang, have values greater than 100. The south and the north are relatively ‘equal’ in terms of the betweenness centrality. Some provinces in both regions play an intermediary role in the spatial network association. The betweenness centrality values of Zhejiang, Fujian, Beijing, Hebei, Liaoning, Shaanxi, and Gansu provinces are 0, which suggests that these provinces do not act as a bridge. This shows that the correlation potential of these provinces needs to be explored.