Abstract
The analysis of the multi-scale evaluation of port city’s international trade goal is conducive to the sustainable development of port city’s international trade. In order to make a more in-depth study on the realization ability of port city’s international trade sustainable development goal, this paper proposes a new multi-scale evaluation method of port city’s international trade goal. This method selects the evaluation indexes, uses the improved normalization method to process the indexes, uses the combination of AHP and factor analysis method to form the subjective and objective combination weighting method, brings the processed indexes into the least square optimization combination evaluation model, calculates the index weight, and uses the fuzzy evaluation method to carry out multi-scale index evaluation on the international trade of port cities to realize its multi-scale evaluation and analysis. The results show that the standardized index of Shanghai’s foreign trade dependence is 0.0056, indicating its independence in international trade. In the comprehensive evaluation, the evaluation values of Shanghai, Tianjin, and Guangzhou are 92.56, 87.89, and 88.45, respectively, which are very close to the actual results, which shows that the accuracy of the evaluation method is high, and provides a theoretical basis for the sustainable development of international trade in port cities.
Keywords
Introduction
International trade has become an important factor in economic growth, so it is crucial to accurately evaluate and analyze the international trade goals of its most important distribution center-port cities. Port cities play a crucial role in promoting global economic development and exchange, but there are still some problems in the development process that affect the sustainable development of their international trade.
In order to achieve sustainable development of international trade in port cities, scholars have conducted extensive research on port cities and achieved some results. For example, Xu et al. studied the impact of international trade on global sustainable development using a data set consisting of 17 Sustainable Development Goals and 169 specific goals. The results indicate that international trade has had a positive impact on achieving global sustainable development [1, 2]. Therefore, the conclusion that export and foreign trade should be regarded as one of the driving forces of national economic growth is drawn, which provides the direction for the foreign sector to pay attention to when building the economic growth forecast and economic policy model; Janssens C et al. used econometric models to analyze the evolution of net foreign trade inflows and the relationship between statistical indicators in order to explore the impact of foreign trade on the economic development of emerging EU countries. The results indicate that out of 9 economies, 7 have a positive impact on net foreign investment inflows from GDP [3]. In addition to the above scholars’ research on international trade in port cities, there are also many scholars who have made their own contributions to enrich the relevant theories of international trade [4].
Although there have been many studies on international trade in coastal cities, there are still shortcomings in the multi-scale evaluation and analysis of international trade goals in port cities, as well as in determining their sustainable development goals. In order to address these issues, this article starts from the sustainable development goals and constructs an indicator system for China’s foreign trade to facilitate sustainable development, including economic development, social population, resource environment, and technological progress. The weight distribution of evaluation indicators is carried out using a combination of subjective and objective weight methods, and a fuzzy comprehensive evaluation model is established to achieve multi-scale evaluation and analysis of international trade goals in port cities [5, 6].
Multi scale evaluation method of international trade target of port city
The sustainable development of foreign trade is the goal of international trade in port cities, but this is not the end point, but a process of continuous improvement. Therefore, when evaluating the international trade goals of port cities, it is necessary to measure their progress in sustainable trade development. Due to the lack of final standards, it is not possible to compare the evaluation object with it. This article only analyzes the gap between the evaluation of international trade goals in a certain year and other years from a time series perspective, or only compares a specific object with other objects in the same year. The evaluation content can be divided into five aspects: structural benefits of trade, economic benefits, social benefits, resource benefits, and environmental benefits. The evaluation methods are mainly divided into subjective evaluation method and objective evaluation method. This article selects the fuzzy evaluation method to evaluate the ability of port cities to achieve the sustainable development goals of international trade. Based on the evaluation content, establish a primary indicator system for evaluating the ability to achieve the sustainable development goals of international trade. Starting from the actual situation of the evaluation object, select appropriate secondary and tertiary indicators, and establish a reasonable evaluation indicator system [7]. Obtain statistical data through various channels, conduct quantitative and qualitative analysis based on fuzzy evaluation method, judge the development trend of international trade goals in port cities, and propose corresponding suggestions for achieving international trade goals in port cities.
Establish a multi-scale evaluation system for international trade objectives of port cities
The goal of international trade in port cities is to integrate the awareness of ecological environmental protection and the concept of sustainable development into every link of the production value chain, which needs to build a set of index evaluation system reflecting the overall status of national and regional international trade development. The system should include economic, social, ecological and other relevant indicators, reflecting the unity of systematicness and pertinence, independence and relevance, static and dynamic, theoretical and feasible, realistic and forward-looking [8].
Systematic and targeted. The index evaluation system is an organic whole, which should cover the scale and benefit of economic development, production and demand, quantity growth and quality improvement and other main aspects, and require representative indicators to be as comprehensive and systematic as possible. However, it is also necessary to avoid information redundancy caused by too many indicators, which is difficult to highlight the main contradiction. Unity of independence and pertinence. Each index should independently reflect the facts of a certain aspect of economic life in order to understand the changes in economic life by analyzing the changes in the index. At the same time, indicators should be linked to each other and complement each other to reflect economic development from multiple angles. The unity of static and dynamic. Horizontal comparability allows the same indicators in different regions to determine the level of regional development in a cross-sectional state. At the same time, the indicators should also have the characteristics of vertical dynamic comparison to truly reflect the development status and development path of regional economic and trade. Unification of theory and feasibility. The international trade goal of port city is the theoretical basis for establishing the evaluation index system of foreign trade sustainable development, and the index system is the external quantitative reflection of the connotation of sustainable development. The unity of realism and foresight. The index system should be able to objectively reflect the actual situation of trade development and guide the actual economic work towards sustainable development [9]. See Table 1 for details.
Multi scale evaluation system of international trade objectives of port cities
It is assumed that the international trade target of port city has
In the decision matrix
The matrix
However, this method also has disadvantages, that is, it does not distinguish the positive and negative indicators. If there is
(1) If there is a reverse indicator, first convert the reverse indicator into a positive indicator through the following formula.
(2) If the
After this treatment, all indicators are non negative, avoiding the limitation that some evaluation methods are not applicable in
(3) Finally, Eq. (1) is used for normalization.
This method can truly reflect the relationship between the original indicators and the advantages of forward and reverse indicators, and overcome the inadaptability of
In the evaluation index system, the importance of each index to the objective and function of international trade system of port city is different. The weight indicates the relative importance of each index or the ratio coefficient of replacing one benefit with another. There are three commonly used methods to determine the weight, namely, subjective method, objective method and combination method. Different methods also include a series of sub methods, as shown in Fig. 1.
Weight calculation method.
Port competitiveness evaluation involves many indexes, each of which reflects the competitiveness of the port from different aspects. The subjective weight method embodies the value (practical significance) of the index, and the objective weight method embodies the information (variation and correlation) of the index. Therefore, in order to make the index weight reach the same subjective and objective, the paper first uses the AHP method for subjective weight, then uses the factor analysis method for objective weight, and finally uses the least square method for subjective weight The objective weight combination method generates the final weight. These three methods are briefly introduced below [11].
In order to make the weights of the evaluation indexes of port city’s international trade objectives reach the same objective and subjective, this paper first uses AHP to weigh the weights of the indexes, which is roughly divided into four steps:
Step 1: According to the multi-scale evaluation system of international trade target of port city, establish the hierarchical structure model. Generally, the number of elements in each layer should not exceed 9. Because psychological experiments show that when the number of elements compared exceeds 9, the accuracy of judgment will decrease [12].
Step 2: Construct the judgment matrix. According to the criterion of adjacent upper level elements, each level element constructs a judgment matrix by comparing the two levels of elements in 1-9 scale method. As shown in Table 2.
1–9 Scale method
1–9 Scale method
Step 3: Hierarchical single sorting and consistency inspection. The maximum eigenvalue and the corresponding eigenvector of the judgment matrix are solved and normalized to obtain the hierarchical single ordering weight vector. Steps of one-time inspection of judgment matrix:
1) The consistency index is calculated as follows:
Among them,
2) The average random consistency index is obtained by querying Table 3.
RI value of average random consistency index
3) Calculate the consistency ratio as follows:
When
4) Level total sequencing and one-time inspection. In practice, the one-time test of total sorting can often be omitted.
After subjectively weighting the weights of international trade target evaluation indexes of port cities by AHP, in order to further make the weights of indexes reach the same objective and subjective, this paper also needs to use factor analysis method for objective weighting. The basic idea of factor analysis is to group the original variables according to the correlation, so that the correlation between the variables in the same group is higher, while the correlation between the variables in different groups is lower. Each group of variables represents a basic structure, which is represented by an unobservable comprehensive variable. This basic structure is the common factor. For a specific problem under study, the original variable can be divided into two parts, one is a few unmeasurable linear functions of the so-called common factor, the other is a special factor unrelated to the common factor [13].
The process of calculating the weight of the evaluation index of port city’s international trade target by factor analysis is as follows:
Step 1: Standardize the original data of port city’s international trade target evaluation index to eliminate the differences in magnitude and dimension between variables (see Chapter 1.2).
Step 2: Find the correlation matrix of standardized data;
Step 3: Find the eigenvalues and eigenvectors of the correlation matrix;
Step 4: Calculate variance contribution rate and cumulative variance contribution rate;
Step 5: Determination factor: set F1, F2 The first m factors can be used to reflect the original evaluation index when the total information of the evaluation index data of port city’s international trade target (i.e. its cumulative contribution rate) contained in the first m factors is no less than 80%;
Step 6: Factor rotation: if the m factors obtained cannot reflect the original evaluation index or their actual meaning is not obvious, then the factors need to be rotated to obtain more obvious actual meaning.
Step 7: Use the linear combination of the original indicators to calculate the factor scores: use regression estimation method, Thomson estimation method to calculate the factor scores.
Step 8: Comprehensive score: take the variance contribution rate of each factor as the weight, and get the comprehensive evaluation index function from the linear combination of each factor.
Here,
Step 9: Ranking of scores: the scores of port city’s international trade target evaluation indicators can be obtained by using comprehensive scores [14]. The specific process of objective weighting in factor analysis is shown in Fig. 2.
Factor analysis objective weighting process.
In order to further calculate, the above two methods are combined to form the subjective and objective weight reorganization, and the weight is analyzed. The weight of each index given by the subjective weighting method is
If the standardized decision matrix of port city international trade target evaluation with
For all indexes of all evaluation objects of port city international trade target evaluation, the smaller the deviation of parity value under subjective and objective weight, the better. For this reason, the following least square optimization combined evaluation model is established.
Solve this model and establish Langrange function as follows:
Order
Expressed as a matrix
Where
Calculate the above matrix equation, and get
In this paper, a fuzzy evaluation method is used to evaluate the ability of port cities to achieve international trade goals. The specific process is as follows:
Step 1: According to Table 1, determine the fuzzy set of the relevant items of the multi-scale evaluation system for the international trade objectives of port cities.
In Eq. (16),
Step 2: Set the evaluation set as
Among them,
Step 3: Determine the weight of each index of the port city’s international trade target realization capacity multi-scale evaluation (see Chapter 1.3).
Step 4: Ddetermine the evaluation membership matrix. According to the multi-scale evaluation of the port city’s ability to achieve the international trade goal, the grade standard is established, and the grade is evaluated by comparing with the standard, and the membership vector of the index to the evaluation set is obtained.
Step 5: Multi factor and multi-level fuzzy comprehensive evaluation.
Step 6: Deal with the evaluation results. After quantifying the elements in the evaluation set
Port city distribution and index data analysis
China has a long coastline and numerous rivers, so there are many port cities. These port cities are located in rivers, lakes, oceans and other waters. They have ports and functions of land and water transport hub. They can be divided into different types according to their geographical location and functional characteristics. This paper takes nine important port cities of Shanghai, Tianjin, Guangzhou, Ningbo, Qingdao, Dalian, Tangshan, Qinhuangdao and Yingkou as examples to analyze the multi-scale evaluation of international trade objectives. As shown in Fig. 3.
Index data of Shanghai in 2020
Index data of Shanghai in 2020
Port city distribution.
In order to quantitatively study the ability to achieve the international trade goals of the nine major port cities in China, this paper collects the required index data in 2020 from the statistical data such as Almanac of China’s Economy, China Commerce Yearbook, China Foreign Economic Statistical Yearbook, The Yearbook of World Economy, China’s Economic and Trade Yearbook, China Labor Statistics Yearbook, and so on Step by step quantitative research on the ability of port cities to achieve international trade goals. First, take Shanghai as an example, and the index data is shown in Table 4.
Standard data of each index
Index weights of Shanghai’s ability to achieve international trade goals
It can be seen from Table 4 that both export and import values of Shanghai are large, indicating its important position in international trade. The degree of Shanghai’s dependence on foreign trade is relatively low, which is 5, indicating that Shanghai has a certain independence in international trade. In terms of the utilization of foreign capital, the data of Shanghai is 22,236, indicating that Shanghai has a certain competitiveness in attracting foreign capital. The product competitiveness coefficient is 6.8, which shows that the competitiveness of Shanghai’s export products is strong. The export ratio of primary manufactured goods was 50.4%, and the export conversion rate of high-tech products was 32.2%, indicating that Shanghai has certain advantages in manufacturing and high-tech industries. The contribution rate of industrial structure is 8.47, and the contribution rate of foreign trade to GDP is 6.87, indicating that Shanghai’s economic growth is closely related to foreign trade and industrial structure optimization. In terms of environment, Shanghai’s export trade wastewater discharge, discharge and waste discharge are high, which may have a certain impact on the environment, and environmental protection needs to be strengthened. The number of employment in foreign trade is 562,522, and the average wage of foreign trade industry is 8522, indicating that the number of employment and wage level of foreign trade industry in Shanghai are relatively high. Specifically, Shanghai performed well in international trade, but continued efforts were needed to optimize industrial structure, improve efficiency and strengthen measures in environmental protection.
According to Section 1.2, standardize the original data of Shanghai’s international trade target capacity, and obtain the standard data of each index as shown in Table 5.
From Table 5, it can be seen that in terms of export and import values, Shanghai’s data are 0.2550 and 0.1523, respectively, which are relatively high, indicating its dominant position in international trade. The product competitiveness coefficient, the output proportion of the secondary industry, and the contribution rate of industrial structure are relatively high. The export proportion of primary manufactured goods, waste emissions from export trade, and the import proportion of resources and resource products are also relatively high. The efficiency of primary products, energy intensity of imports and exports, and the proportion of service trade are relatively low. Comprehensive analysis shows that Shanghai’s international trade target capacity exhibits varying degrees of advantages and disadvantages in various aspects, requiring reasonable policy planning and industrial structure adjustment.
Index weight calculation
Through the weight calculation method in Chapter 1.3, the weight of each index of Shanghai’s ability to achieve international trade goals is calculated, as shown in Table 6.
From Table 6, it can be seen that there are differences in the weights of various indicators of Shanghai’s ability to achieve international trade goals. Among them, indicators such as the proportion of primary manufactured goods exports, regional trade differences, the proportion of secondary industry output, the proportion of service trade, and foreign trade employment have high weights, indicating that these indicators have a significant impact on Shanghai’s ability to achieve international trade goals. Analysis shows that these indicators with higher weights are mainly concentrated in industrial structure, trade policies, and human resources. Therefore, in order to enhance Shanghai’s international trade target capacity, it is necessary to focus on these aspects and take corresponding policy measures. At the same time, we should also strengthen support for foreign trade employment and increase the average wage level in the foreign trade industry. Specifically, adjusting indicators with higher weights and adopting corresponding policy measures can help improve Shanghai’s ability to achieve international trade goals.
Comprehensive evaluation results
According to Chapter 1.4, the evaluation results of Shanghai’s urban international trade objectives are obtained. In the same way, the weights of international trade objectives of other port cities are calculated by single factor analysis and single analytic hierarchy process, and then the fuzzy evaluation method is also used for analysis. The final results are shown in Table 7.
Comprehensive evaluation results
Comprehensive evaluation results
Note: the real results are obtained from the comprehensive analysis of China Foreign Economic Statistics Yearbook and 100 experts, which are of high reference value.
It can be seen from Table 7 above that the score of the development capacity of international trade target of 9 port cities obtained by the evaluation method in this paper is closer to the actual result, while the calculated score is quite different from the actual result based on the weight obtained by the single factor analysis method and the single level analysis method. This shows that the accuracy of this evaluation method is high, which provides a theoretical basis for the sustainable development of international trade in port cities [16].
Although the concept and development strategy of sustainable development of foreign trade have been generally accepted by people, if a concept and development strategy is transformed into a government operational management mode, it is necessary to establish a set of evaluation index system and related evaluation methods to evaluate its development degree. At present, the evaluation index system of international trade objectives of port cities in China has developed, but the research on the evaluation methods of international trade objectives of port cities in China is still rare and some of the evaluation methods have too much error. Therefore, this paper attempts to use the subjective and objective combination of weighting method and fuzzy evaluation method to achieve a more accurate evaluation of the port city’s international trade objectives, which has been proved to be more accurate. However, due to the availability of data, only objective second-hand statistical data are used in the selection of evaluation indicators, and no qualitative indicators are used. The experimental results indicate that Shanghai’s foreign trade dependence index is 5, indicating its independence in international trade. The product competitiveness coefficient of Shanghai is 6.8, indicating its strong trade competitiveness. The standardized values of Shanghai’s international trade import and export data are 0.2550 and 0.1523, respectively, proving Shanghai’s dominant position in international trade. The above conclusion proves the effectiveness of the research design method. Although this method avoids the subjective problem, the evaluation index system constructed in this paper still needs to be improved. Therefore, the future researchers can further improve the evaluation index system of port city competitiveness.
