arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2104.06911stat.MEmath.STstat.TH
收藏

带有无效工具变量的因果推断:选择后问题及基于搜索与抽样的解决方案

Causal Inference with Invalid Instruments: Post-selection Problems and A Solution Using Searching and Sampling

Zijian Guo

AI总结:

本文针对无效工具变量难以与有效工具变量区分时现有置信区间覆盖不足的问题,提出结合搜索与抽样的方法构造一致有效且更精确的置信区间,并在R包RobustIV中实现。

摘要:

工具变量方法是观察性研究中处理未测量混杂因素的最常用因果推断方法之一。无效工具变量的存在是实际应用中的主要问题,而一个快速发展的研究领域是在可能存在无效工具变量的情况下对因果效应进行推断。本文说明,当有效工具变量和无效工具变量难以通过数据驱动的方式区分时,现有的置信区间可能会出现覆盖不足的问题。为了解决这一问题,我们构造了一致有效的置信区间,该区间对区分有效和无效工具变量时的错误具有稳健性。我们提出搜索一系列能够产生足够多有效工具变量的处理效应值。我们进一步设计了一种新颖的抽样方法,该方法与搜索相结合,可以得到更精确的置信区间。我们提出的搜索与抽样置信区间具有一致有效性,并在有限样本多数规则和多数相对规则下达到参数化长度。我们将所提出的方法应用于考察教育对收入的影响。所提出的方法已在R包RobustIV中实现,可从CRAN获取。

英文摘要:

Instrumental variable methods are among the most commonly used causal inference approaches to deal with unmeasured confounders in observational studies. The presence of invalid instruments is the primary concern for practical applications, and a fast-growing area of research is inference for the causal effect with possibly invalid instruments. This paper illustrates that the existing confidence intervals may undercover when the valid and invalid instruments are hard to separate in a data-dependent way. To address this, we construct uniformly valid confidence intervals that are robust to the mistakes in separating valid and invalid instruments. We propose to search for a range of treatment effect values that lead to sufficiently many valid instruments. We further devise a novel sampling method, which, together with searching, leads to a more precise confidence interval. Our proposed searching and sampling confidence intervals are uniformly valid and achieve the parametric length under the finite-sample majority and plurality rules. We apply our proposal to examine the effect of education on earnings. The proposed method is implemented in the R package RobustIV available from CRAN.

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。

↑