摘要

隨著國際分工從產業間分工到產業內分工，再到產品內分工的深化和發展，收入分配不均、工資差距擴大和非熟練勞動力失業增加成為多國共同面臨的難題。許多國家包括美國、中國，國內各類勞動力間工資及收入差距擴大的時期，正是其參與國際產品內分工加速深化的階段。因此，國際產品內分工對收入分配的影響成為近二十年來國際經濟學界的研究熱點和研究前沿。

在多邊國際產品內分工體系中，各國參與產品內分工的行業技術密集度及所負責的生產工序技術密集度存在明顯的差異，形成了不同的國際產品內分工模式。但現有研究，特別是經驗研究，鮮有基于不同模式來實證分析產品內分工對收入分配的影響。鑒于此，本書以對不同產品內分工模式的識別、測度為切入點和創新點，重點研究不同生產及國際產品內分工模式的組合對各類技能或教育程度勞動力的收入分配影響。

本書將產品內分工分為低端型國際產品內分工和高端型國際產品內分工。前者表現為一國從事低技術工序的生產，需進口高技術中間投入品；后者表現為一國從事高技術工序的生產，需進口低技術中間投入品。通過對HS（1996）六分位每一類進口中間產品的技術復雜度與各國自身的各年度總出口技術復雜度進行比較，本書創新性地實現了對各國進口的每一類中間產品進行動態分類，并據此測算高、低端型產品內分工水平。

在國際產品內分工對不同技能勞動力收入分配影響的理論分析方面，本書在深入剖析、比較各理論模型的作用機制和效應后，指出：國際產品內分工對不同技能勞動力相對需求、相對工資的影響渠道包括直接作用機制與間接作用機制，其中，直接作用包含要素需求創造效應和要素替代效應，間接作用包含產品價格效應和國際產品內分工引致的有偏型技術進步效應。通過上述四個作用渠道，高、低端型產品內分工模式對不同要素密集型部門的各類技能勞動力產生了不同的相對需求和工資效應。

基于45個主要國際產品內分工參與國（地區）1998—2012年的高、低端產品內分工水平測算，研究發現，45個國家大致可劃分為四個梯隊，形成了顯著的中心—外圍格局，其中，29個發達國家分屬三個不同梯隊，16個發展中國家除印度外均屬最外圍的第四梯隊。中國目前尚處于第四梯隊中，不過，中國的低端型產品內分工水平與高端型產品內分工水平的差距正在逐步縮小。觀察各行業的BEC 法垂直專業化指數，發現當前中國以高技術部門、進行低端型產品內分工為主。其中，低技術部門已逐步從以低端型產品內分工為主轉變升級為以高端型產品內分工為主，但高技術部門升級乏力。

本書還分別從國內行業層面和多國宏觀層面，對國際產品內分工模式的收入分配效應進行了實證分析。來自中國工業部門的經驗分析顯示，低端型和高端型產品內分工均會顯著提高中國熟練勞動力的工資份額，其中，低端型產品內分工通過進口中間產品技術溢出間接地影響收入分配，而高端型產品內分工則通過要素替代直接影響收入分配。基于多國宏觀面板數據的經驗分析顯示，高、低端型產品內分工分別顯著降低了低、高等教育勞動力的報酬份額，國際產品內分工水平的綜合效應相對偏向中等教育勞動力，不過，該有利影響主要發生在發展中國家。由于在低端型產品內分工模式下，高技術中間投入品進口有利于技術溢出、模仿創新，因此，該模式引致的技術進步偏向中等教育勞動力；而高端型產品內分工倚重自主創新，因此，其引致的技術進步偏向高等教育勞動力。

基于上述研究結論，提出的政策啟示為：應加快改善中國勞動力供給的技能結構；實施生產分工局部提升與區域分散化戰略，加快提升沿海地區高技術部門在國際產品內分工中的競爭優勢和分工地位；鼓勵內陸地區承接沿海地區的轉移產業，適當保護低技術部門進行低端型國際產品內分工。

關鍵詞：國際產品內分工模式 收入分配 技能溢價 教育溢價進口中間產品 技術復雜度

ABSTRACT

With the development and evolution of international division of labor from inter-industry specialization to intra-industry specialization, and to intra-product specialization, more and more countries have to face the rising income inequality, wage gap and the unemployment of unskilled labor.The widening of the income and wage gap among workers of many countries including U.S.and China concurred with the accelerative deepening of intra-product specialization.Since then the research of international intraproduct specialization's impact on income distribution has become a hot and advancing topic in international economics in recent 20 years.

In the multilateral international intra-product specialization, different sectors of different countries often undertake different technological intensive components of production process, which leads to different intra-product specialization patterns.But few existing research, especially the empirical research, has been based on different patterns to empirical analysis of the effects of international intra-product specialization.For this reason, this paper distinguishes and estimates different patterns of international intraproduct specialization as the breakthrough and innovation points, focusing on the effects of various patterns on the income distribution among workers who possess different skill capabilities and educational attainment.

The study distinguishes international intra-product specialization between the low-level and high-level patterns.In the low-level pattern, one country or sector undertakes low-tech fragments and imports hightech intermediate inputs.On the other hand, in the high-level pattern，one country or sector undertakes high-tech fragments and imports lowtech intermediate inputs.In order to estimates the low-level and high-level patterns, the study classifies dynamically all imported intermediate inputs （at the 6-digit level of HS 1996）into two categories based on their technology intensities by comparing the TSI（Technological Sophistication Index） of each imported intermediate input with the TSI of the corresponding country per year.

This paper analyzes theoretically how international intra-product specialization affects the income distribution between skilled labor and unskilled labor.Based on comparative analysis of the existing theoretical model, the paper proposes four direct and indirect effects of international intra-product specialization on relative demand and relative wage of workers with different levels of skill capabilities.Direct effects are factor substitution effect and factor demand creation effect, while the indirect effects include product-price change effect and technological improvement induced by international intraproduct specialization.Through these four channels, the low-level and high-level patterns of international intra-product specialization have different influence on worker's relative demand and relative wage within different technological intensive sectors.

After distinguishing and measuring the main 45 economies' low-level and high-level pattern of international intra-product specialization from 1998 to 2012, the study finds that 45 economies can be categorized into four groups from the core to the periphery, of which 29 developed economies belong to three different groups, 16 developing countries except India as the peripheral fourth group.China is now still belonging to the fourth groups.However, the gap between low-level and high-level pattern of China's international intra-product specialization has decreased gradually.According to the Vertical Specialization Share with BEC method, international intra-product specialization pattern of China is characterized by high-tech sectors with low-level pattern.Meanwhile, the low-tech sector has changed step by step from low-level pattern to high-level pattern of international intra-product specialization.However, there is no evidence of upgrading in the high-tech sectors.

The paper examines empirically the link between international intraproduct specialization and the income distribution respectively with a crossindustry panel data of China and a cross-country panel data of 45 economies.Based on China's industries' dynamic panel data, the paper finds that both low-level pattern and high-level pattern of intra-product specialization increase the wage share of skilled labor.The low-level pattern indirectly affects the income distribution through technology spillovers of skilled-intensive intermediate imports; while the high-level pattern of intra-product specialization directly affects the income distribution through factor substitution.Based on the cross-country panel data, the empirical results indicate that the low-level pattern of intra-product specialization has significantly decreased the wage share of workers with a high level of education, while the high-level pattern has impacted negatively upon the wage share of workers with a low level of education.The net effects of the intra-product specialization tend to shift labor demand towards workers with an intermediate level of education in developing countries.Through technology spillovers of skilled-intensive imported intermediate inputs and imitation innovation, the technological progress induced by low-level pattern is associated with a shift in labor demand towards to workers with an intermediate level of education, while the high-level pattern of intra-product specialization towards to workers with a high level of education due to independent innovation.

Based on above results, this paper puts forward some policy implications, such as increasing relative supply of skilled labor; adopting regional diversification strategies; supporting high-tech industries in coastal provinces of China to improve their competitive advantages and win higher status in global production sharing; encouraging inland provinces to undertake in dustries transferred from coastal area and properly protecting low-tech industries deepening low-level pattern of intra-product specialization.

Key Words: Pattern of international intra-product specialization;Income distribution; Skill premium; Education premium; TSI of imported intermediate inputs