An Evaluation of Instrumental Variable Strategies for Estimating the Effects of Catholic Schooling
评估了宗教归属和天主教学校距离作为工具变量的有效性，发现现有数据中这些工具变量无法有效识别因果效应，并探讨了双变量Probit模型中排除限制与非线性的识别作用，为其他应用中的工具变量评估提供了模板。
Several previous studies have relied on religious affiliation and the proximity to Catholic schools as exogenous sources of variation for identifying the effect of Catholic schooling on a wide variety of outcomes. Using three separate approaches, we examine the validity of these instrumental variables. We find that none of the candidate instruments is a useful source of identification in currently available data sets. We also investigate the role of exclusion restrictions versus nonlinearity as the source of identification in bivariate probit models. The analysis may be useful as a template for the assessment of instrumental variables strategies in other applications.