中文摘要：

本文通过全球投入产出模型研究发现：若全球生产网络体系正常运转，垂直关联并没有放大外生最终需求冲击对全球贸易下滑的影响，反而在一定程度上缓解了全球贸易下滑。中间产品贸易的下降幅度远低于最终需求产品贸易，但因权重为2／3，其贡献率较大（49％以上）；非垂直专业化值与垂直专业化值的下降幅度基本一致，因后者权重较小，其对全球贸易的贡献率低于28％。进一步比较真实统计数据计算结果表明：一旦供给侧遭到外生冲击，全球生产网络体系遭到破坏，垂直关联中断，将导致中间产品贸易和垂直专业化贸易大幅下降，进而造成全球贸易大幅下滑。

英文摘要：

A common but controversial view： vertical linkages （especially international vertical spe- cialization） have exacerbated the global trade decline. This paper uses a global input-output framework to simulate the impacts of vertical linkages. It shows that, if the global production network operates normally, then the vertical linkages do not aggravate, and sometimes even alleviate to certain extent, the fall of the global trade. The decline of the trade of intermediate products is far less than the decline of the final products. However, since the trade of the intermediate products consists of two thirds of the total trade, it explains as large as 49% of the global trade decline. The decline of non-vertical specialization and vertical specialization are almost the same. Due to the smaller weight of the latter, the decline of vertical specializa- tion explains less than 28% of the global trade decline. After comparing with the estimation results of real data, this paper shows that： once the supply side suffered exogenous shock, and the global production network, as well as, vertical linkages was destroyed, the trade of intermediate products and vertical specialization would decline sharply, triggering the global trade to collapse.