Abstract

Fuzzy regression discontinuity designs identify the local average treatment effect (LATE) for the subpopulation of compliers, and with forcing variable equal to the threshold. We develop methods that assess the external validity of LATE to other compliance groups at the threshold, and allow for identification away from the threshold. Specifically, we focus on the equality of outcome distributions between treated compliers and always-takers, and between untreated compliers and never-takers. These equalities imply continuity of expected outcomes conditional on both the forcing variable and the treatment status. We recommend that researchers plot these conditional expectations and test for discontinuities at the threshold to assess external validity. We provide new commands in STATA and MATLAB to implement our proposed procedures.

摘要

模糊回归不连续性设计确定了合规者亚群的局部平均治疗效果（LATE），并且强迫变量等于阈值。我们开发了一些方法来评估LATE在阈值范围内对其他合规性小组的外部有效性，并允许从阈值范围之外进行识别。具体来说，我们专注于处理过的编纂者和始终接受者之间以及未处理过的编撰者和永不接受者之间的结果分布相等。这些相等性意味着预期结果的连续性取决于强制变量和治疗状态。我们建议研究人员绘制这些条件期望并在阈值处测试不连续性，以评估外部有效性。我们在STATA和MATLAB中提供了新命令来实现我们提出的过程。