The analysis of natural direct and principal stratum direct effects has a controversial history in statistics and causal inference as these effects are commonly identified with either untestable cross world independence or graphical assumptions. This article demonstrates that the presence of individual level natural direct and principal stratum direct effects can be identified without cross world independence assumptions. We also define a new type of causal effect, called pleiotropy, that is of interest in genomics, and provide empirical conditions to detect such an effect as well. Our results are applicable for all types of distributions concerning the mediator and outcome.

中文翻译：

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在没有跨世界假设的情况下识别个体水平多效性、纯直接效应和主要层直接效应


对自然直接效应和主要层直接效应的分析在统计学和因果推理中具有争议性的历史，因为这些效应通常通过不可测试的跨世界独立性或图形假设来识别。本文证明，无需跨世界独立性假设，就可以识别个人层面的自然直接影响和主要阶层直接影响的存在。我们还定义了一种新型的因果效应，称为多效性，这在基因组学中很有趣，并提供了检测这种效应的经验条件。我们的结果适用于有关中介和结果的所有类型的分布。