Abstract:     Since its reform and opening-up, especially its accession to the WTO, China has rapidly integrated into the global production network with the advantage of labor force. However, the core high-tech intermediates in China′s manufacturing industry still need to be imported. China′s manufacturing industry may be "solidified" in the processing and assembly links with low value added for a long time, and the technical level of export products may be overestimated. Therefore, the relationship between integration into global value chain and real export sophistication deserves further exploration. By analyzing the impact of integration into the global value chain on the technical level of export products in manufacturing industry, we can understand the status of global value chain and real trade benefits from the perspective of commodity technology structure. It is of great significance for improving product technology and domestic value added and adjusting the industrial structure in the global production network.
    This paper analyzes the influence mechanism, and finds that vertical specialization has an impact on the technical level of export products through technology spillover effect, productivity and competitiveness enhancement effect, and cost effect. High quality intermediate input helps downstream sectors to absorb and improve relevant technologies, and the feedback from downstream sectors also helps the suppliers optimize technologies. Participation in vertical specialization focuses on different links of the value chain based on the scarcity of factors. Through three aspects of production, technology and market, it acts on factor accumulation, technology spillover and market expansion, and ultimately improves productivity and international competitiveness. In terms of cost, vertical specialization promotes the scale and standardization of production. Cost sharing can relatively reduce the cost of information exchange, transportation, management and other aspects, simplify the supervision, transaction and other complex processes, and further promote R&D and innovation.
    From the perspective of research, this paper calculates the export sophistication by considering the industrial correlation effect of domestic upstream sectors, and analyzes the technical upgrading effect of integration into global value chain. In terms of research methods, the paper uses the latest version of the World Input-Output Database continuous data from 2000 to 2014 to measure the vertical specialization level of China′s manufacturing industry, and then measures the export sophistication of China′s manufacturing industry based on the domestic value added in gross exports. During the period of 2000-2014, the export sophistication of the manufacturing industry is increasing. Labor intensive sector has the highest export sophistication, which also conforms to the current situation of China′s export. In terms of research conclusion, this paper confirms the positive impact of integration into the global value chain on technical level, but finds that manufacturing industry fails to effectively integrate with human capital.
    This paper empirically tests the impact of GVC embeddedness on the technical level of export products in manufacturing industry. The results show that the deepening of integration into the global value chain promotes the export sophistication of China′s manufacturing industry. At the same time, we find that human capital accumulation does not promote technology upgrading in the short term. For the manufacturing industry, especially for the departments with long production cycle, it may take a long time for human capital to improve the technical level, while "resource competition" occurs in the same period, so the impact of human capital is significantly negative. According to the analysis of the segmented sectors, with the deepening of China′s manufacturing industry integration into the value chain, the export sophistication of labor intensive and capital-intensive sectors has been improved, while the export sophistication of technology intensive sector has no obvious correlation with the embedding of global value chain. We analyze that this is related to the way of China′s integration into the value chain. In the early stage of reform and opening-up, China was faced with the conditions of relatively abundant labor force and insufficient supply of capital elements. In the vertical specialization division mode led by multinational corporations, manufacturers without core technologies will be locked in the low-end, so it is difficult to achieve the high value-added link of the global value chain. Vertical specialization promotes technical progress and value chain status of developing countries, but it also makes developing countries face the risk of "low-end locking" and "immiserizing growth".
    According to the above research, there are the following corresponding policy implications. First, China′s manufacturing industry can participate in the international division of labor in a diversified way and allocate resources more reasonably according to the comparative advantages of each region. Manufacturing industry needs to actively improve its technical level through the "learning by doing" effect and promote the transformation and upgrading of export trade structure. Second, for the problem of "resource competition" in human capital, the servitization of manufacturing can improve the marginal effect of human capital. Manufacturing industry can rapidly combine high-level services with human capital of the industry, rely on advanced technology and services, shorten production cycle, and make full use of human capital. Third, for sectors with "low-end locking", especially technology intensive sector, it is necessary to gradually get rid of the dependence on foreign intermediate products. We can rely on the rapid growth of domestic demand market scale to cultivate the ability of independent innovation, form a complete supply network in China, and then integrally embed into the global value chain. 

Key words:  vertical specialization, export sophistication, domestic value added (DVA), human capital