Tests of the Three-Path Mediated Effect
研究了在三路径中介模型中检验中介效应的六种方法，通过蒙特卡洛模拟比较其第一类错误率、统计功效和覆盖率，推荐联合显著性检验用于假设检验，百分位和偏差校正自助法用于置信区间估计。
In a three-path mediational model, two mediators intervene in a series between an independent and a dependent variable. Methods of testing for mediation in such a model are generalized from the more often used single-mediator model. Six such methods are introduced and compared in a Monte Carlo study in terms of their Type I error, power, and coverage. Based on its results, the joint significance test is preferred when only a hypothesis test is of interest. The percentile bootstrap and bias-corrected bootstrap are preferred when a confidence interval on the mediated effect is desired, with the latter having more power but also slightly inflated Type I error in some conditions.