准实验偏离-份额研究设计
Quasi-Experimental Shift-Share Research Designs
摘要：
许多研究使用转移份额（或"巴蒂克“）工具，用风险份额权重对一组冲击进行平均。我们提供了一个新的计量经济学框架的转移份额工具变量（SSIV）回归，其中识别遵循准随机分配的冲击，而暴露份额被允许是内生的。该框架的动机是一个等价的结果：偏移-份额工具和不可观测残差之间的正交性可以表示为潜在冲击和冲击水平不可观测之间的正交性。SSIV回归系数同样可以从等效冲击级回归中获得，激励冲击级条件的一致性。我们在Autor et al.（2013）的背景下讨论并说明了这一框架的几个实际见解，估计了中国进口竞争对美国通勤区制造业就业的影响。
英文摘要：
Many studies use shift-share (or ``Bartik'') instruments, which average a set of shocks with exposure share weights. We provide a new econometric framework for shift-share instrumental variable (SSIV) regressions in which identification follows from the quasi-random assignment of shocks, while exposure shares are allowed to be endogenous. The framework is motivated by an equivalence result: the orthogonality between a shift-share instrument and an unobserved residual can be represented as the orthogonality between the underlying shocks and a shock-level unobservable. SSIV regression coefficients can similarly be obtained from an equivalent shock-level regression, motivating shock-level conditions for their consistency. We discuss and illustrate several practical insights of this framework in the setting of Autor et al. (2013), estimating the effect of Chinese import competition on manufacturing employment across U.S. commuting zones.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
