全球化中的中国垂直专业化再分解:集约边际与扩展边际

Decomposition of China's Vertical Specialization Fluctuation: Intensive versus Extensive Margins

"垂直专业化"(Vertical Specialization,VS)是各国经济彼此联系的重要渠道之一。我们在Hummels等(2001)与Hummels和Klenow(2005)的工作基础上,提出了一个新的分解框架:将VS的波动分解为集约边际变动、扩展边际变动、国际因素等四个因素,并利用该方法分解了中国1995-2010年VS的变动。结果表明:(1)中国VS的增长主要是通过已有产品出口数量的扩张达到的,集约边际变动对VS变动(均值)贡献达到了74.026%,而扩展边际的贡献相当小。(2)国际因素是中国VS扩张中的重要因素,其对中国VS变动(均值)贡献为25.95%。(3)两类产业的VS受国际冲击最为强烈,一类是国际纵向分工网络发达,中国VS参与程度较深的产业;另一类是中国因资源禀赋或技术能力而严重依赖进口的行业。

Vertical Specialization has become one of the most important eco- nomic interaction channels between countries. Following Hummels and Klenow （2005） and Hummels et al. （2001）, this paper decomposes China＇s vertical spe- cialization （VS） fluctuation into four contributing factors, including intensive mar- gins, extensive margins and international factors etc. By applying this methodolo- gy on China＇s trade, our study finds that： （1） Growth of VS in China is mainly achieved through the expansion of trading volumes of existing products; 74.026% of the change of VS is caused by intensive margins on average. （2） The interna- tional economic shock is another significant contribution to the expansion of VS, contributing to 25.95% of its change on average. （3） The VS of two types of in- dustries are mostly affected by international economic shocks. The first type is those industries that have been deeply involved in the well-developed internation- al vertical linkages; the other is the industries that rely heavily on imports be- cause of limited resource endowment or technical capability.