| 来源类型 | Working Paper |
| 规范类型 | 报告 |
| DOI | 10.3386/t0343 |
| 来源ID | Technical Working Paper 0343 |
| Do Instrumental Variables Belong in Propensity Scores? | |
| Jay Bhattacharya; William B. Vogt | |
| 发表日期 | 2007-09-14 |
| 出版年 | 2007 |
| 语种 | 英语 |
| 摘要 | Propensity score matching is a popular way to make causal inferences about a binary treatment in observational data. The validity of these methods depends on which variables are used to predict the propensity score. We ask: "Absent strong ignorability, what would be the effect of including an instrumental variable in the predictor set of a propensity score matching estimator?" In the case of linear adjustment, using an instrumental variable as a predictor variable for the propensity score yields greater inconsistency than the naive estimator. This additional inconsistency is increasing in the predictive power of the instrument. In the case of stratification, with a strong instrument, propensity score matching yields greater inconsistency than the naive estimator. Since the propensity score matching estimator with the instrument in the predictor set is both more biased and more variable than the naive estimator, it is conceivable that the confidence intervals for the matching estimator would have greater coverage rates. In a Monte Carlo simulation, we show that this need not be the case. Our results are further illustrated with two empirical examples: one, the Tennessee STAR experiment, with a strong instrument and the other, the Connors' (1996) Swan-Ganz catheterization dataset, with a weak instrument. |
| 主题 | Econometrics ; Estimation Methods ; Health, Education, and Welfare ; Health ; Education |
| URL | https://www.nber.org/papers/t0343 |
| 来源智库 | National Bureau of Economic Research (United States) |
| 引用统计 | |
| 资源类型 | 智库出版物 |
| 条目标识符 | http://119.78.100.153/handle/2XGU8XDN/571077 |
| 推荐引用方式 GB/T 7714 | Jay Bhattacharya,William B. Vogt. Do Instrumental Variables Belong in Propensity Scores?. 2007. |
| 条目包含的文件 | ||||||
| 文件名称/大小 | 资源类型 | 版本类型 | 开放类型 | 使用许可 | ||
| t0343.pdf（217KB） | 智库出版物 | 限制开放 | CC BY-NC-SA | 浏览 | ||
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