[论文解读] The World Trade Web: A Multiple-Network Perspective

Paolo Sgrignoli|arXiv (Cornell University)|Jan 1, 2014

Global trade and economics参考文献 109被引用 6

一句话总结

本文利用多网络框架研究国际贸易、移民与外国直接投资（FDI）之间的相互作用。通过网络分析与空间计量经济学方法，发现制造业中贸易与FDI呈互补关系，而服务业中则呈替代关系，地理距离与供应链位置显著影响二者关系，区域贸易协定则增强了替代效应。

ABSTRACT

International Trade (IT) plays a fundamental role in today's economy: by connecting world countries production and consumption processes, it radically contributes in shaping their economy and development path. Although its evolving structure and determinants have been widely analyzed in the literature, much less has been done to understand its interplay with other complex phenomena. The aim of this work is, precisely in this direction, to study the relations of IT with International Migration (IM) and Foreign Direct Investments (FDI). In both cases the procedure used is to first approach the problem in a multiple-networks perspective and than deepen the analysis by using ad hoc econometrics techniques. With respect to IM, a general positive correlation with IT is highlighted and product categories for which this effect is stronger are identified and cross-checked with previous classifications. Next, employing spatial econometric techniques and proposing a new way to define country neighbors based on the most intense IM flows, direct/indirect network effects are studied and a stronger competitive effect of third country migrants is identified for a specific product class. In the case of FDI, first correlations between the two networks are identified, highlighting how they can be mostly explained by countries economic/demographic size and geographical distance. Then, using the Heckman selection model with a gravity equation, (non-linear) components arising from distance, position in the Global Supply Chain and presence of Regional Trade Agreements are studied. Finally, it is shown how IT and FDI correlation changes with sectors: they are complements in manufacturing, but substitutes in services.

研究动机与目标

• 通过多网络视角，检验国际贸易、移民与FDI之间的相互依存关系。
• 利用拓扑与计量经济方法，识别贸易与移民网络之间的结构性与因果关系。
• 评估FDI与贸易在不同部门中的互动关系，重点关注地理因素、供应链位置与区域贸易协定的影响。
• 利用Heckman两步模型，厘清FDI与贸易流量中的内生性与选择效应。
• 量化网络拓扑结构与经济规模如何塑造贸易与FDI之间相关性。

提出的方法

• 基于国家层面的贸易与FDI数据，构建两个加权有向网络：世界贸易网络（WTW）与国际FDI网络（FDIN）。
• 应用网络拓扑度量（度、强度、平均最近邻度、异配性）比较WTW与FDIN的结构性特征。
• 采用空间计量经济方法，包括引力模型与Durbin模型，分析移民与贸易的互动关系。
• 使用Heckman两步选择模型校正样本选择偏差，并估计移民与FDI对贸易的因果影响。
• 在引力模型中引入与距离、上游度及区域贸易协定（RTA）的交互项，以评估异质性效应。
• 应用泊松回归与稳健性检验，验证引力模型设定与选择模型的表现。

实验结果

研究问题

• RQ1 国际贸易与移民网络之间存在何种相关性？哪些产品类别表现出最强的重叠？
• RQ2 直接与间接移民渠道在多大程度上影响贸易流量？其影响如何随产品类型而变化？
• RQ3 FDI与贸易之间存在何种因果关系？该关系在不同部门与地理区域中如何变化？
• RQ4 区域贸易协定与地理距离如何影响FDI与贸易之间的互补或替代关系？
• RQ5 产品在全球供应链中的位置（上游度）如何影响FDI与贸易的关系？

主要发现

• 总体上，贸易与FDI呈正相关，但关系因部门而异：制造业中二者为互补关系，服务业中则为替代关系。
• 在初级（原材料）部门，FDI与贸易出口呈替代关系，但贸易与FDI进口之间无显著关系。
• 距离对FDI与贸易之间的相关性具有正向交互效应，即地理距离越远，FDI与贸易的相关性越强。
• 供应链中下游（更接近最终用途）的产品表现出更强的FDI与贸易互补性，而上游产品则呈现替代关系。
• 区域贸易协定（RTA）与贸易呈正相关，并增强了FDI与贸易之间的替代效应。
• 亚洲国家展现出更高的贸易量以及更强的FDI与贸易互补性，进一步巩固其作为全球生产枢纽的地位。