Interpreting Instrumental Variables Estimates of the Returns to Schooling
结合理论模型与计量方法，解释工具变量估计如何加权个体因果效应，并以大学距离为例，分析该工具对高中到大学阶段的影响最大，同时检验了模型稳健性。
AbstractThis article synthesizes economic insights from theoretical models of schooling choice based on individual benefits and econometric work interpreting instrumental variables estimates as weighted averages of individual-specific causal effects. Linkages are illustrated using college proximity to instrument for schooling. After characterizing groups differentially affected by the instrument according to family background, I directly compute weights underlying estimation of the overall return. In analyzing the level of schooling at which individuals change their behavior in response to the instrument, I demonstrate that this instrument has its greatest impact on the transition from high school to college. Specification robustness is also examined.KEY WORDS: Average causal response weighting functionTwo-stage least squaresWages