1. Introduction
In the context of global economic growth, global partnership cooperation and the construction of innovative infrastructure in various countries have been gradually promoted. The development of international trade and port logistics has a certain role in promoting the adjustment of industrial structure and economic growth in the hinterland. Industry, infrastructure, economic growth, and global partnership as global sustainable development goals are also a subset of international trade and port logistics development. In addition, the promotion effect of the development of international trade on hinterland enterprises effectively promotes the improvement of employment rate, solves the residents’ work, and promotes the growth of urban economy to a certain extent. The development of the port logistics level represents the enhancement of the competitiveness of logistics, port-related enterprises, and the manufacturing industry, which plays an important role in social development. At the same time, the improvement of the port logistics level effectively improves the efficiency of port operations and reduces the waste of resources and environmental pollution caused by cargo handling, transportation, turnover, and storage. Therefore, port logistics and international trade are related to sustainable development, and the coordinated development of port logistics and international trade has a certain promoting effect on national (regional) sustainable construction. In 2020, China’s total import and export trade reached USD 4655.91 billion, an increase of 26 percentage points compared with 2016. The rapid growth of total trade import and export has put forward new requirements for the logistics service level of China’s coastal ports. The development of coastal ports is closely related to international trade, and the enhancement of the international logistics level plays a role in promoting the development of international trade. At the same time, the development of international trade promotes the level of international logistics. With the implementation of the ‘Belt and Road’ Initiative, coastal ports, as an important part of international logistics channels, also play an important role in the development of international trade. However, there are still many problems in the process of sustainable development of China’s coastal port logistics and international trade, which have widely concerned scholars at home and abroad.
At the end of the 20th century, Liao [
1] made a relevant explanation of the concept of coordinated development, believing that development refers to the process of change of the event itself, and coordination focuses on the relationship between different events. Therefore, coordinated development reflects the common characteristics of “development” and “coordination”, that is, the development model of improving the overall evaluation level in the process of benign interaction, emphasizing integrity, comprehensiveness, and internality. The coordinated development of port logistics and international trade is conducive to promoting a higher level of sustainable development in the region. In order to explore the sustainable development relationship between coastal port logistics and international trade, based on the relevant data from 2016 to 2020, the entropy weight method is used to calculate the weight of each index and the coupling coordination model is constructed. According to the research results, specific suggestions are put forward to promote the sustainable development of port logistics and international trade and provide reference for the sustainable development of countries (regions).
The second section after this section combs the relevant literature of this study. The third section introduces the research indicators and data sources, and expounds the research methods used. The fourth section analyzes the empirical results in detail. Part 5 puts forward relevant suggestions based on empirical analysis to promote better sus-tainable development of coastal port logistics and international trade. The sixth section summarizes the empirical results.
2. Literature Review
At present, most of the research on international logistics focuses on the direction of port logistics, and the related research on port logistics is mainly based on the evaluation of port logistics development and the exploration of the relationship between port logistics and the regional economy. Ye et al. [
2] systematically studied the development of port logistics along the Yangtze River from 2004 to 2014 and concluded that there is a big gap in the development of port logistics in different areas along the Yangtze River. The development level of port logistics in the eastern region is higher than that in the western region, and the urban supporting factors have the greatest influence on the development of port logistics. Wu et al. [
3] explored the synergy mechanism of coastal ports in Jiangsu Province from the perspective of synergy and believed that the synergy degree of Lianyungang, Yancheng Port, and Nantong Port was unstable. Havenga et al. [
4] made a systematic study on the cost of international trade logistics in South Africa, pointed out the problem of terminal costs and the lower international trade logistics costs occupied by the Port Authority, and believed that scarce resources should be reasonably allocated after fully understanding the relationship between the port and the national logistics system. Huang [
5] believes that foreign trade promotes the development of port logistics in the Guangdong–Hong Kong–Macao Greater Bay Area, and there are problems such as lack of talents and unreasonable allocation of resources in its port logistics development. Yao et al. [
6] used the DEA–Malmquist model combined with the data from 2000 to 2018 to study the port logistics efficiency of Shanghai Port. The analysis shows that the logistics efficiency of Shanghai Port is in a state of continuous growth in the time series, but the dynamic efficiency value is fluctuating or even declining, and before 2017, the comprehensive technical efficiency value of Shanghai Port has not yet reached the DEA effective state. Liu et al. [
7] used the grey correlation degree and factor analysis method to explore the influencing factors of port logistics in countries along the Belt and Road. It was found that among the influencing factors, the transportation, cost, and infrastructure of the port have a significant impact on the development of port logistics. In the related research on the relationship between port logistics and the regional economy, Li et al. [
8] carried out a synergistic study on the port logistics efficiency and hinterland economic development in Liaoning Province. Through empirical analysis, it was found that the synergy degree between port logistics development and the hinterland economy in Liaoning Province showed an increasing trend in the time series, and the synergy degree in coastal areas was higher than that in inland areas. Xu [
9] believed that the scale of ports and cities, the location of ports, and port facilities have a certain impact on the evolution of hinterland space. Guo et al. [
10] explored the coordinated development of Tangshan port logistics and its hinterland economy under the time series of 2006–2016. The analysis showed that the synergy between Tangshan port logistics and its hinterland economy showed an increasing trend. Cao et al. [
11] believed that with the advance of time, the synergy degree of Taicang Port’s logistics and hinterland economic development is also increasing. Chen [
12] used the entropy weight method and constructed a synergy degree model in the study of the coordinated development of Shanghai Port’s logistics and Shanghai’s economy and concluded that the degree of coordination between Shanghai Port’s logistics development and Shanghai’s economic development is on the rise as a whole.
In the relevant research on the influencing factors of international trade, Hu et al. [
13] believed that energy, communication networks, and transportation have different effects on national trade imports and exports. Wang et al. [
14] used the difference-in-difference method to study the relationship between international trade and enterprise innovation. The analysis shows that the number of enterprise patent applications has an increasing trend with the opening of the ‘China-Europe Express’ and taking export trade as an intermediary. Khan et al. [
15] explored the impact of renewable energy on international trade and environmental quality, arguing that renewable energy is closely linked to international trade in Nordic countries and that renewable energy policies have a positive effect on environmental quality improvement and economic development. Shi et al. [
16] used empirical analysis to explore the impact of digital government on international trade with 168 countries and regions as samples and verified that digital government can promote international trade, and this effect increases with the increase of national income level. Hayakawa et al. [
17], based on an analysis of 34 countries’ exports to 173 countries, concluded that COVID-19 had a negative impact on international trade in both importing and exporting countries but a positive impact on medical products.
Zhu et al. [
18] studied the development relationship between port logistics and foreign trade in Hebei Province by constructing a VAR model with time samples from 1990 to 2011. The analysis shows that there is a mutual promotion between port logistics development and foreign trade. The development of port logistics has a short-term effect on the promotion of foreign trade, while the promotion of foreign trade has no short-term effect on the development of port logistics, and their mutual influence effect is more significant in the long run. Cho et al. [
19] pointed out in their study of the impact of global protectionism on port logistics that under the blessing of trade protectionism, the combination of tariff barriers and non-tariff barriers would reduce the demand for maritime logistics services and have a negative impact on international trade, which is not conducive to the global trade order and the development of global maritime logistics. Wu [
20] studied the relationship between port logistics and international trade by using the grey correlation analysis method and the VAR model and believed that the relationship between trade, port cargo throughput, and port container throughput is balanced.
In summary, in the related research of port logistics, the coordinated development of port logistics and the regional economy and the impact of port logistics development on international trade are more common. The related research on port logistics and regional economies mostly adopts the research methods of the gravity model, synergy model, and Granger causality test. The research on the coordinated development of coastal port logistics and international trade still needs to be further enriched.
3. Materials and Methods: Index Sources and Model Construction
3.1. Indicator Selection
At present, the main indicators of coastal port logistics development include coastal port cargo throughput, container throughput, terminal length, number of berths, etc.; cargo throughput is the basic evaluation index of port logistics development; container throughput is an important output index for evaluating port logistics development; and the development of international trade is more evaluated by the authoritative total import of goods, the total export of goods, or the total import and export of goods. Based on the availability of data and the research of Wang et al. [
21], the index system is established as shown in
Table 1. The coastal port logistics system is measured by three dimensions: coastal port logistics scale, coastal port logistics development prospects, and coastal port logistics infrastructure. Six evaluation indexes are selected, including cargo throughput, container throughput, cargo throughput growth rate, container throughput growth rate, coastal port terminal length, and coastal port terminal berths. The international trade system is measured in two dimensions: international trade scale and trade prospects. In addition, select the total imports of goods, total exports of goods, total imports of goods growth rate, and total exports of goods growth rate of four evaluation indicators.
The internal interaction between coastal port logistics and international trade is shown in
Figure 1. The growth of international trade promotes the expansion of the scale of port logistics and the prospects for coastal port logistics. It also promotes the improvement of port infrastructure, thus promoting the sustainable development of infrastructure. Paying attention to the construction of coastal port infrastructure plays a protective role in the transportation, import, and export of international trade goods. This paper explains the benign interaction between coastal port logistics and international trade from the perspective of the internal coordinated development mechanism of the two subsystems and verifies the coordinated development degree and trend of the two subsystems by the empirical method in the following chapters.
3.2. Model Construction
In the method of measuring the objective weight of multiple indicators, the entropy method has been widely used in academia. Based on the research experience of previous scholars, in order to judge the dispersion degree of different indicators of the two subsystems of coastal port logistics and international trade, the entropy method is used to measure the index weight of each subsystem. Firstly, the normalization method is used to standardize the data of each index to eliminate the influence of objective factors such as the difference of measurement units on the research results. The indexes in this study are all positive indexes, and the processing formula is as follows:
where
represents the coastal province,
.
represents the index,
,
represents the result of the
index of province
after standardization,
represents the original value of the j index of province
,
represents the maximum value under the
index, and
represents the minimum value under the
index.
According to the standardized processing results of the data, the proportion of each index data is calculated:
Among them, represents the proportion of index of coastal province .
The entropy value of the
th index is:
where
, and
,
denotes the entropy of the index
,
.
Calculating the coefficient of variation for indicator
:
Determining the weight of indicator
:
Calculate the comprehensive evaluation score of each index with:
Among them, represents the year, , represents the comprehensive evaluation score of the coastal port logistics development in province in year , and represents the comprehensive evaluation score of the international trade development in province in year .
On the basis of the above obtained index weights and the comprehensive evaluation scores of coastal port logistics and international trade in six different provinces, the coupling coordination model of China’s coastal port logistics and international trade is constructed. The coupling coordination model originates from physics research to measure the interaction between two or more different systems. The relationship is applied to this article to measure the level of synergy between coastal provinces and international trade, and the coupling degree of the two subsystems is expressed as follows:
Among them, and represent the weights of the two subsystems of port logistics development and international trade development, respectively. This study believes that the coastal port logistics and international trade are mutually influential and equally important. Therefore, both and are 0.5. is the number of subsystems. This paper uses two subsystems of coastal port logistics and international trade, so is 2. represents the coupling coordination level of coastal port logistics and international trade in province in year , ; the higher the value of is, the higher the coupling coordination degree is, and vice versa.
Comprehensive evaluation index:
where
represents the comprehensive evaluation index of coastal port logistics and international trade development in province
in year
.
Coordinated development:
where
represents the coordinated development degree of coastal port logistics and international trade development in
province in
years. Referring to the research of Liao [
1], the division standard of coordinated development degrees of coastal port logistics and international trade is as shown in
Table 2.
4. Results: Empirical Analysis
According to the data of the WTO in 2021, China’s total import and export goods are ranked first in the world, reaching about USD 6 trillion. Combined with the provinces where China’s large-scale coastal ports are located and the evaluation of trade scale, six coastal provinces, namely Tianjin, Liaoning, Shanghai, Jiangsu, Zhejiang, and Shandong, were selected as the research areas, with 2016–2020 as the time interval; it is representative to explore the coordinated development of coastal port logistics and international trade. Considering the availability of data in the six provinces (cities) and the size of the coastal ports in each province (city), the most representative ports were selected to obtain the index data of the coastal port logistics subsystem. Among them, the Tianjin coastal ports are represented by Tianjin Port, the Liaoning coastal ports are represented by Dalian Port and Yingkou Port, the Shanghai coastal ports are represented by Shanghai Port, the Shandong coastal ports are represented by Qingdao Port, the Jiangsu coastal ports are represented by Lianyungang Port, and the Zhejiang coastal ports are represented by Ningbo-Zhoushan Port. The index data of international trade in this study are from the ‘National Statistical Yearbook’ and the ‘Ministry of Transport of the People’s Republic of China’. The coastal port logistics index data are from the China Shipping Database and the National Bureau of Statistics.
Through the entropy weight method, the index weights in each system were calculated. In the coastal port international logistics system, the weight of cargo throughput in coastal ports is 0.16845, the weight of container throughput in coastal ports is 0.15963, the weight of cargo throughput growth rate is 0.19147, the weight of container throughput growth rate is 0.19084, the weight of port terminal length is 0.15964, and the weight of terminal berth number is 0.12997. In the international trade system, the weight of total export trade is 0.22414, the weight of total import trade is 0.23132, the weight of total export trade growth rate is 0.27447, the weight of total import trade growth rate is 0.27007. Combined with the weight of each index, the results of the coordinated development of coastal port logistics and international trade were further calculated as shown in
Table 3. From the data in
Table 2, the trend chart of the coordinated development of coastal port logistics and international trade and the trend chart of the growth rate of the coordinated development of each province are shown in
Figure 2 and
Table 3.
It can be seen from
Table 3 and
Figure 2 that the coordinated development degree of coastal port logistics and international trade in Shanghai and Zhejiang Province is above the overall average. Combined with the criteria in
Table 2, the coordinated development degree of Shanghai will reach 0.803 in 2020, and the coordinated development degree of Zhejiang Province will be 0.836 in 2020, reaching a good coordinated development stage, exceeding other coastal provinces (cities). In addition to Zhejiang Province and Shanghai, the coordinated development degrees of Jiangsu Province and Shandong Province are also in the coordinated development range. The higher coordinated development degrees of the four provinces is related to the development level of large-scale coastal ports and the volume of import and export trade. From 2016 to 2020, Shanghai, Shandong, Jiangsu, and Zhejiang had a total annual import and export trade of more than USD 200 billion, far higher than Liaoning and Tianjin. Ningbo-Zhoushan Port in Zhejiang Province and Shanghai Port in Shanghai are among the top ten ports in the world. The cargo throughput and container throughput of Ningbo-Zhoushan Port and Shanghai Port exceed those of Tianjin Port, Lianyungang Port, Qingdao Port, Dalian Port, and Yingkou Port. From 2016 to 2020, the cargo throughput of Ningbo-Zhoushan Port and Shanghai Port ranked second among the six provinces (cities). In 2017, the cargo throughput of Ningbo-Zhoushan Port exceeded 1 billion tons, reaching 1.17 billion tons in 2020. In addition, the container throughput of Shanghai Port ranked first among the six provinces (cities), reaching 43.5 million tons in 2020, followed by Ningbo-Zhoushan Port. The large scale of port logistics, infrastructure construction, and import and export trade volume are the important reasons for the coordinated development of international trade and coastal port logistics in Zhejiang and Shanghai.
From an overall perspective, the average coordinated development degree of coastal port logistics and international trade was no more than 0.800 from 2016 to 2020, which has a large space for development. Moreover, the coordinated development degree of coastal port logistics and international trade in Tianjin, Liaoning, and Jiangsu provinces is below the average value of the coordinated development degree of coastal cities. As China’s second largest economic province, Jiangsu Province’s container throughput in Lianyungang has not exceeded 5 million tons in recent years. As an inland port, Suzhou Port needs to transfer some foreign trade exports through Shanghai Port, which is also the reason why the development level of coastal port logistics in Jiangsu Province is not prominent in China’s coastal provinces. Liaoning Province and Tianjin also have problems such as weak connectivity of coastal port facilities, unreasonable port layout planning, and low resource utilization [
22]. There is still a certain gap compared with the coastal port logistics in Zhejiang Province and Shanghai.
As shown in
Table 4, among the coastal provinces (municipalities) in 2019, the average coordinated development growth rates of Liaoning, Tianjin, Shandong, Shanghai, Jiangsu, and Zhejiang were all negative; that is, the coordinated development degree in 2018–2019 showed a downward trend. In early 2018, the United States launched a trade war with multiple countries, including China, increasing tariff and non-tariff barriers, which caused a certain negative impact on China’s import and export trade, and was also the important reason why the coordinated development growth rate of China’s coastal port logistics and international trade showed a downward trend or even turned negative. Even at the end of 2018, China and the United States stopped the new tariffs during the G20 summit, but the impact on China’s international trade had a continuing effect. The growth rate of the coordinated development of coastal port logistics and international trade in many coastal provinces (cities) of China still showed a downward trend in 2019.
5. Discussion
With the growth of the economy, coastal port logistics and international trade are in a development trend. The internal elements of the two are positively interactive and harmonious. Port logistics and international trade are closely related to sustainable development. The coordinated development of port logistics and international trade also has a certain effect on the process of regional sustainable development. According to the empirical analysis of the coordination degree of the development of coastal port logistics and international trade in six provinces (cities) of China, this paper puts forward some suggestions to promote the sustainable development of coastal port logistics and international trade and provides reference for the direction of national sustainable development:
(1) Strengthening the innovative construction of coastal port infrastructure and promoting the smooth operation of the low-carbon operation mode and international trade. There is still some room for improvement in the hardware facilities and operation mode of coastal ports. Encouraging innovation in technology and management modes, promoting more green and low-carbon port operations, strengthening the construction of green and environmentally friendly ports, fundamentally improving the hardware development system of coastal ports, and improving the efficiency of coastal port operations are effective ways to promote the development of coastal port logistics, thereby enhancing the competitiveness of ports in international trade and contributing to the sustainable development of coastal port logistics and international trade.
(2) Improve the optimal allocation of resources and deepen international trade cooperation with import and export countries. Improving the rationality of coastal port resource allocation and strengthening the construction of deep water and container berths play important roles in promoting the high-quality development of coastal port logistics. At the same time, we should strengthen the consensus on trade openness with other countries, accelerate the construction of “smooth trade“ and “road connectivity“ in the Belt and Road Initiative, connect with the 21st Century Maritime Silk Road, strengthen cooperation with coastal ports of corresponding import and export countries, achieve a wider range of information and supply sharing, build a network cooperation model between coastal ports, promote the development of coastal port logistics and international trade, and form a higher level of coordinated development.
6. Conclusions
In the context of the implementation of China’s One Belt and One Road strategy, accelerating the construction of sustainable development of coastal port logistics and international trade will help enhance their own strength and enhance the country’s international competitiveness. This paper uses the entropy weight method and constructs a coupling coordination model. Through the discussion of the sustainable development of port logistics and international trade, the conclusion of the development of China’s coastal port logistics and international trade from 2016 to 2020 is drawn:
(1) The coordinated development degree of coastal port logistics and international trade in six provinces (cities) of China is not obvious during the period of 2016–2020, and there is a discontinuous decline in 2019. From the overall perspective, there is still much room for improvement in the coordination degree of China’s coastal port logistics and international trade.
(2) From the perspective of location, the coordinated development degree of Shanghai and Zhejiang’s coastal port logistics and international trade is higher than other coastal provinces (cities), and the coordinated development degree of Shandong Province and Jiangsu Province in 2020 ranks behind. Compared with the coastal provinces (cities) in the coordinated development zone, some ports in the maladjusted provinces have the problem of large but scattered berths and unreasonable resource allocation, especially the lack of large deep water and container berths.