4.3. The Results
Based on the additive two-stage network DEA model with shared inputs and undesirable outputs, we estimate the overall and sub-stage sustainability of railway of 30 provinces in China from 2002 to 2013 by using LINGO software. We set the weight of each stage to be:
=
= 0.5. The lower and upper bounds of proportion of shared labor in first stage are specified as 0.2 ≤
≤ 0.4, according to the reality of China’s railways. By solving Equation (13) through the two-step method discussed in the methodology section, we can get the average evaluation result for overall sustainability of railway transportation, which is showed in
Table 3 (the detailed descriptive statistics for overall sustainability performance can be found in
Appendix A).
(1) The changing trend of the overall sustainability performance of railway transportation across the country. The results in
Table 3 indicate that the overall sustainability of railway transportation in China is slightly above the middle level from 2002 to 2013, specifically locating in a high growth interval of 0.5737–0.7703 centered at 0.6775, which still has a large amount of room for improvement. The overall sustainability of railway transportation in China is inefficient, and as we discussed in the methodology section, this means that at least one stage is inefficient: either the production stage or the service stage, or both of them. We will identify the exact inefficient stage in the sub-stage analysis part. From the changing trend in Figure 4, we can find that the sustainability of railway transportation across the country presents a trend of declining first, rising after, and declining again, during the study period:
Firstly, it gradually declines from 2002 to 2005 and reaches the bottom by 2005. In 2002, China’s Ministry of Railways put forward the strategy of “Railway Leap-forward Development”, hoping to expand railway mileage by increasing investment and to improve railway technical equipment to reach the most advanced level in the world. This strategy leads to every province’s large investment in railway projects in China: the annual growth of fixed asset investment of railways is up to about 40% during that period. During the “11th Five-Year Plan” period, the national total railway operating mileage reached 91,000 km and the total length of rapid passenger transportation network reached to more than 20,000 km. However, after three decades of increasing marginal returns, the marginal return of railway investment starts to decline. To pursue the growth of GDP, some regional governments invest in many railway projects, which exceed their needs and have inconspicuous economic and social benefits. Those excessive railway projects result in a waste of resources and cause much pollution to the environment. Hence, the sustainability performance keeps falling in that period.
Afterwards, the sustainability of railway transportation keeps rising from 2005 to 2009, which benefits from the transformation of the direction of government regulation and the development of high-speed railway technology. China’s State Council promulgates the “Mid-to-Long Term Railway Network Plan” in 2005, highlighting the importance of railway technology innovation. Following it, the Ministry of Railways issues the “Mid-to-Long Term Railway Network Plan (Adjusted in 2008)” in 2008, shifting the railway construction orientation from emphasizing on quantity to emphasizing on quality, which leads to the steady increase of the sustainability of railway transportation. Moreover, with the Sixth Round Speed-up Campaign of railways in 2007, China officially entered the era of high-speed railways. The Leapfrog development of high-speed rail technology brings great economic and social benefits, and creates breakthroughs both in energy-saving and environmental protection in China.
However, sustainability performance presents a descending trend after 2009. This is partly because of the follow-up effect of the “Four-trillion Economic Stimulus Plan” after the international financial crisis in 2008. In addition, different regions in China have been increasing investment to railway infrastructure so as to stimulate economic growth. Until 2014, the new scale of railway production in China hits a record size, and the railway mileage exceeds 112,000 km, among which the high-speed railway mileage reaches more than 16,000 km and ranks first in the world. Although the total amount of railway infrastructure expands obviously, the planning of railway network in some places is unreasonable. In order to pursue high standard and high-speed railway, some investment projects become difficult to control. The growth rate of railway investment is then much larger than that of transportation revenue. Additionally, the investment in technology innovation of railway is far from enough, the environment pollution generated in railway construction is not well controlled, and the execution of environmental regulation is inadequate, which all result in the increasing of environmental pollution year by year. All of the above factors cause the declining of the sustainability of railway transportation during this period.
(2) The regional difference analysis of the overall sustainability of railway transportation. According to the partition method used by China Statistics Bureau on 13 June 2011, in this paper, we divide the 30 provinces into three groups: eastern area, central area, and western area (the eastern area includes Beijing, Tianjin, Shanghai, Hebei, Shandong, Jiangsu, Zhejiang, Fujian, Guangdong, Liaoning, Hainan; the central area includes Shanxi, Henan, Hubei, Anhui, Hunan, Jiangxi, Inner Mongolia, Guangxi, Heilongjiang, Jilin; and the western area includes Xinjiang, Ningxia, Shanxi, Gansu, Qinghai, Chongqing, Sichuan, Guizhou, Yunnan), and the location of these provinces can be seen from the map of China in
Figure 3. We then estimate and compare the changing trend of the sustainability of railway transportation in these three areas (shown in
Figure 4). During the observation period, the average sustainability performance values of railway transportation in eastern, central and western areas are respectively 0.7310, 0.6471, and 0.6460, which reflects that the sustainability of eastern railway transportation is much better than that of the central and western areas. The latter two areas’ sustainability performance values of railways are similar and the central area is slightly better.
Figure 4.
Overall sustainability of railway transportation in China.
Figure 4.
Overall sustainability of railway transportation in China.
To further investigate the difference of the sustainability of railway transportation among these three areas, we adopt the Mann-Whitney U-tests [
40] to verify the difference between each of them. If the
p-value of the Mann-Whitney U-tests are less than 0.05, we will reject the null hypothesis that there is no difference between the medians of the two populations. The results shown in
Table 4 present that there are obvious differences between the eastern areas and the other two areas, while the latter two are close. The differences reflect that the level of economic development has a great influence in the sustainable development of railway transportation, which is to say that provinces with higher levels of economic development (like the eastern areas) pay more attention to the sustainability of railway transportation, while provinces with relative lower level of economic development (like the central and western areas) have the relative low level of railway sustainable development. In fact, the relationship between regional economic development and railway transportation is a reciprocal causation: economically developed provinces have larger demand for railway investment, as well as a higher request for the sustainability of railway transportation, and sustainable railway transportation, in turn, will promote economic growth.
The distribution of the numbers of effective DMUs (sustainability performance value = 1) in different years also proves the above conclusion. Evaluation results show that effective DMUs mainly concentrate in eastern coastal provinces (Beijing, Tianjin, Shanghai, and Hainan), among which the sustainability of railway transportation in Tianjin has reached the effective status for 10 consecutive years (2002–2011) during the study period. The sustainable development of railway transportation in eastern coastal areas firstly benefits from the sufficient investment provided by the developed economy and finance there. Then the innovation of railway technology, such as the upgrading of locomotives, which is represented by high-speed railways, reduces the negative impact to the environment. Additionally, in these areas, there are denser populations and thriving businesses that generate great demand for railway transportation, so railway development can bring obvious social welfare effects. Finally, the local governments there pay more attention to energy conservation and environmental protection than the governments in other areas of China. All of these factors bring about the harmonious development of railways, population, and economy.
From the dynamic perspective of the differences, we can find that the gap of sustainability performance between the eastern areas and the other areas narrows gradually from 2002 to 2009, but it amplifies again after 2009. This reveals that the strategies Rise of Central China Plan and China’s Western Development Program applied before 2009 contribute to the reduction of the gap. The central and western areas have much poorer railway infrastructure compared with the eastern area in the beginning, which means greater marginal economic and social benefit of railway investment and larger resource and environment space to be utilized; therefore, the gap in sustainability gradually becomes narrower. However, after 2009, this later-mover advantage of the central and western areas gradually disappears, and lots of investment in railway infrastructure there still does not pays attention to the coordinated development of railway transportation with the economy, population, and environment, leading to the decline in sustainability. By contrast, the new round of infrastructure investment in the eastern area pays more attention to the quality of railway infrastructure, environmental protection, and social development. Thus, the sustainability of railways there can be improved and the gap between the two areas becomes wider. It is noteworthy that the sustainability of western areas surpasses that of central areas after 2009. On the one hand, this may be caused by the significant support of the central government to the western area; on the other hand, it also indicates that the western areas pay more attention to the coordinated development on economy, environment protection, and society than the central areas. The central areas need to learn advanced experiences from other areas in railway transportation development and break the dilemma of “Central Depression”.
(3) The sub-stage sustainability performance of railway transportation. Railways are a complicated and large system, and the interaction between sub-stages plays a significant role in the overall sustainability of railway transportation. If and only if both of the two sub-stages are effective can the overall sustainability of railway transportation be effective. Thus, when the optimal overall efficiency
is obtained, we can get the corresponding optimal efficiency for stage 1,
associated with the optimal overall efficiency
, and then calculate the optimal efficiency for stage 2 as
.
Table 5 shows the average evaluation results for the sub-stage sustainability of railway transportation in different areas of China (the detailed descriptive statistics for sub-stage sustainability performance can be find in
Appendix A).
From
Table 5, we can see that the sustainability of railway production and service stages both present inefficient (efficiency value < 1) during the sample period. The efficiency of production stages is lower than that of service stage, which means production stage has a greater impact on the overall sustainability of railway transportation. In the production stage of railway in China, the construction technology is not mature enough, the equipment is not advanced and the overall level of project construction is not high enough. Therefore, the cost benefit ratio of railway construction is low, but its damage to environment is serious, which eventually becomes the main cause of inefficiency of the production stage. However, the inefficiency in service stage is mainly because of the use of non-renewable energy (coal) during the operation process of railway, which then causes serious pollution to the environment. The noises of railways during their operation should also be considered. In addition, the irrationality of the planning of railway routes in China also causes the waste of resources in the process of railway operation and finally results in the inefficient state of sustainability.
From the national perspective,
Figure 5 shows that sustainability efficiency in the first stage declines first, then rises, and finally declines. This is consistent with the overall changing trend of sustainability, and the corresponding inflection points are also consistent. However, the changing trend of the sustainability in the second stage showed in
Figure 6 presents different characteristics: it declines from 2002 to 2007 and keeps rising since 2007. The results certify that the present overall sustainability efficiency of railway transportation in China is mainly affected by the first stage (the production stage), so the improvement of railway construction and technological innovation is the priority task in current China to improve the overall sustainability of railway transportation, and the enhancement of the service efficiency of railway after 2007 corresponds to the fact that China formally steps into the era of high-speed railway in 2007, which proves that the leapfrog development of high-speed railway technique prompts a significant improvement on railway service efficiency. Thus, China should unswervingly develop high-speed railway technology and enhance the sustainability of railway operation.
From the perspective of different areas, the average efficiency values of the first stage in the eastern, central, and western areas are separately 0.5943, 0.5053, and 0.4727 during the study period. The efficiency of eastern areas is better than that of central areas, and the latter is better than that of the western areas. The average efficiency values of the second stage in the eastern, central, and western areas are, separately 0.8677, 0.7889, and 0.8193, where the efficiency of the eastern area is better than that of the other areas, but the west is slightly better than the middle. From the view of changing trends, the changing trends of efficiencies of the three areas are almost the same in the first stage. Moreover, the gap between the eastern areas and the rest areas experiences a period of declining in early stage, and tends to expand since 2009, which is consistent with the changing trend of overall sustainability. However, in the second stage, the changing trends of the efficiency values are similar in the eastern and the central areas, while the western areas are different from them. The service efficiency in western areas overtakes that in eastern and central areas, which illustrates that the western areas do better in harmonious development of economy, environment, and society in the service process. This also indicates that the primary cause of the expansion of the gap in railway sustainability between the eastern and other areas is the expansion of the gap in production efficiency, which is brought by the gap in the technology level of railway construction. As a consequence, in order to narrow the gap, the central and western areas should make full use of national supportive policy, introduce and absorb the advanced green technology and management experiences from the eastern areas.
In summary, the inefficiency of the production stage contributes more to the inefficiency of the overall sustainability for China’s railway transportation. There are two reasons for this observation. One reason is that the efficiency value of the production stage is much lower than that of the service stage, which means that the production stage has a greater impact on the overall sustainability, as the overall efficiency is the weighted mean of the two efficiencies with both weights being 0.5. The other reason is that the overall changing trend of the sustainability is consistent with the changing trend of the production stage, and their corresponding inflection points are also consistent; however, it is not the case between the changing trend of the service stage and the overall changing trend. Moreover, the inefficiency of the production stage of railway in China may be caused by the immature construction technology, the backward equipment, and the low level of project construction.