Intra-industry trade is the manifestation of the above-mentioned division of labor, which has developed very rapidly since the 1960s and is also reflected in western international trade theory. Gruber and P.J. Leo yd's work in 1975 has a great influence, and their definitions and measurement methods are widely accepted by academic circles. Intra-industry trade means that a country exports and imports a certain kind of products at the same time. The so-called similar products are classified according to the United Nations three-digit standard international trade classification. SITC classifies commodities in international trade into 10 category, which is divided into 63 categories, 233 subcategories, 786 subcategories and 2000 basic items. In other words, products belonging to the same "group" are similar products, but some people have adopted a looser classification standard, that is, products belonging to the same "department" are similar products. The formula they proposed is as follows:
(Z[，i]+M[，i])-|Z[，i]-M[，i]|
B[，I]=——————× 100
(Z[，i]+M[，i])
The above formula can also be written as.
|Z[，i]-M[，i]|
B[，I]=( 1-——————————)× 100
(Z[，i]+M[，i])
In the above formula, B[, i] is an indicator of intra-industry trade, which is called G-L index. When it changes between 0- 100, it tends to 100, indicating that the higher the level of intra-industry trade is. I refers to industry, z refers to export and m refers to import. Their research with other western scholars shows that (1) intra-industry trade mainly occurs in the manufacturing industry in developed countries. According to the OECD data, more than 60% of the manufacturing industries in the six western European countries were intra-industry trade in 199 1 year, and the proportion in the other six western European countries was 50% ~ 60%. (2) Intra-industry trade of manufactured goods is much higher than that of primary products. The highest industries are machinery and transportation equipment and chemical industry. The higher the technology intensity, the greater the tendency of intra-industry trade. (3) A country's economic growth is closely related to the level of intra-industry trade. According to the above, we can regard the world G-L index as a production index reflecting globalization, because the greater the G-L index, the higher the interdependence of countries in production specialization. The main form of intra-industry division of labor is the specialization of the same product with different grades and quality or just different models and scales, such as exporting a large number of cars of several brands and importing a large number of cars of other brands. There is also the specialization of parts or technological processes, and all relevant enterprises participate in cooperation to complete the final product. China's processing trade can be said to belong to the latter form, which is completed by importing raw materials and parts for processing and assembly, and then exporting them.
Since the reform and opening up, China's processing trade has developed rapidly. In the mid-1980s, the export of processing trade was only $5.6 billion, accounting for only 18% of China's total export, while the proportion of general trade was as high as 82%. However, by 195, the amount of processing trade had increased to $74 billion, which increased by 12 times in 10, and its proportion also increased. By 1996, the amount of processing trade had increased to 10447 billion US dollars, which was nearly 18 times higher than that in the mid-1980s, accounting for about 57%. Processing trade accounts for a higher proportion of foreign-funded enterprises' exports, accounting for 45% of China's total exports at present, and its growth momentum is far stronger than that of state-owned enterprises. Therefore, it can be said that processing trade is the main supporting force for the sustained and rapid growth of China's foreign trade in the past decade and plays an irreplaceable role. Processing trade has expanded the employment scale in China. According to the announcement of Guangdong Province, 1997, the province's processing trade accounted for about 55% of the total processing trade in China, and absorbed about 100000 people's employment. It is estimated that about 20 million people in China have found jobs in this way. Processing trade has also promoted the improvement of processing technology in China and promoted the growth of some manufacturing sectors. Some of them started from scratch. Household appliances, for example, started from assembly and later grew into an industry with certain competitive advantages in the world. Since the reform and opening up, the proportion of China's manufactured goods exports has surpassed that of primary products in a relatively short period of time, which is inseparable from the development of processing trade. It can be seen that processing trade does provide a good opportunity for us to participate in and make use of intra-industry division of labor.
However, processing trade has also brought us troubles and contradictions, which are mainly related to the dual mechanism in foreign trade. In order to support processing trade, the required intermediate products are exempted from import duties, and at the same time, each region has its own preferential measures, so a set of parallel processing trade promotion mechanisms has been formed outside the general trade promotion mechanism, which has caused the following contradictions:
1. The promotion mechanism of general trade mainly lies in the realization of zero-tax export by export tax rebate, while the export of processing trade is only given tax rebate if it creates value in China. In principle, both make sense and can go hand in hand. However, when the export tax rebate for general trade is not fully in place, some enterprises will switch from general trade to processing trade, especially those enterprises that need to import high-tariff raw materials and intermediate products, so as to reduce the import of raw materials and intermediate products by general trade, thus affecting the country's tariff revenue.
2. If the processing process is concentrated in the export processing zone or bonded zone, it is convenient for the customs to implement effective supervision. However, China's processing trade has no geographical restrictions, and it is scattered from the coast to the inland, which is really difficult to supervise. In addition, foreign trade enterprises have the right to operate but lack the processing capacity, while production enterprises have the processing capacity but do not have the right to operate, and there are many loopholes because of the disconnection between industry and trade, which gives criminals an opportunity to resell bonded imported raw materials and intermediate products in China and reap huge profits. For example, about half of the major smuggling cases seized by the customs in 1997 were conducted through processing trade channels.
It must be pointed out that the above contradiction is not caused by processing trade itself, but by international division of labor. As long as the two parallel mechanisms are constantly coordinated and balanced, the contradiction can be solved. The central government has made up its mind to combat smuggling in an all-round way. At the same time, in 1997, the bank established a processing trade account system, and the customs and foreign exchange administration further strengthened the verification measures for the import and export of processing trade. Therefore, the illegal activities of smuggling in processing trade are being curbed.
At present, the main problem of processing trade is that it is still at a low level, which is characterized by "two ends are outside, big imports and big exports", that is, raw materials and parts are supplied by customers or imported from abroad by themselves, and the finished products after processing and assembly enter the overseas market through the sales channels mastered by customers. China enterprises only use labor resources and charge limited labor fees, but if they want to earn more foreign exchange, they have to import and export. In order to further develop the potential of intra-industry division of labor and share greater benefits, we must speed up the upgrading of processing trade. The key is to do a good job in the import substitution of intermediate products, that is, to replace foreign intermediate products with more domestic components, so that more links in the international value chain of products can be transferred to China, which can not only increase the domestic added value of products, increase foreign exchange income, but also expand the links with domestic upstream and downstream related industries, so that processing trade can play a greater role in promoting economic growth.
Looking back at the two energy crises in the early 1970s and the late 1970s, western developed countries were forced to speed up the adjustment of industrial structure, and a series of industries gradually moved outward. Newly industrialized countries and regions in East Asia also transplanted labor-intensive manufacturing industries to Chinese mainland. It is under this historical opportunity that China's processing trade has sprung up. Among them, the more successful household appliances have developed from processing and assembly into a mature industry and started to enter the world market. In the current process of economic globalization, the developed countries headed by the United States are carrying out a new round of industrial upgrading, and the intra-industry division of labor is developing in depth, which objectively presents new opportunities. With proper policies and measures, China's processing trade can climb to a higher level.