The ‘China Shock’ revisited: insights from value added trade flows
利用贸易增加值分解方法重新评估中国进口对美国地方劳动力市场的影响，发现传统贸易数据高估了冲击规模，且2008年后负面影响已不明显。
Abstract We exploit a decomposition of gross trade flows into their value added components to reassess the relationship between increased imports from China and manufacturing jobs in US local labour markets following the seminal paper of Autor, Dorn, and Hanson (2013, ADH). Decomposed trade flows enable us to address identification and measurement issues inherent to gross trade data. In particular, it allows us to remove US value added in Chinese exports from the exposure measure which is mechanically correlated with the dependent variable and overstates the volume of the trade shock. In addition, the decomposition permits to correct for double counting, to remove primary and services inputs in manufacturing exports, and to assign competition to the upstream industry that supplied the value added rather than the final exporting industry. This further reduces the volume of the shock and improves the accuracy of the import exposure measure. Consequently, we find considerable differences in the pattern of regions that are most affected by the trade shock and show that imports from China can explain less of the decline in US manufacturing than what gross trade data would suggest. We then separate the shock into a China-driven domestic reform and a third-country-driven value chain component, and find in line with ADH that the smaller, but still negative labour market effects are indeed China driven. Finally, we observe that the negative effects identified in ADH are not present in the 2008–2014 period, which is in line with the hypothesis that labour market adjustment has largely concluded.