This study aims to test the theory underlying Job Corps, one of the largest education and training programs in the U.S. serving disadvantaged youth. Central to the program are vocational training and general education that serve as two concurrent mediators transmitting the program impact on earnings. To distinguish the relative contribution of each, we develop methods for decomposing the Job Corps impact on earnings into an indirect effect transmitted through vocational training, an indirect effect transmitted through general education, and a direct effect attributable to supplementary services. We further ask whether general education and vocational training reinforce each other and produce a joint impact greater than the sum of the two separate pathways. Moreover, we examine the heterogeneity of each causal effect across all the Job Corps centers. This article presents concepts and methods for defining, identifying, and estimating not only the population averages but also the between‐site variance of these causal effects. Our analytic procedure incorporates a series of weighting strategies to enhance the internal and external validity of the results and assesses the sensitivity to potential violations of the identification assumptions.

中文翻译：

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作业公司评估中站点之间复杂的调解机制及其异质性

这项研究的目的是检验作为美国最大的为弱势青年服务的教育和培训计划之一的Job Corps的理论基础。该计划的核心是职业培训和通识教育，它们是两个同时进行的调解人，传递该计划对收入的影响。为了区分每个人的相对贡献，我们开发了一些方法来分解工作队对收入的影响，使其分解为通过职业培训传递的间接影响，通过通识教育传递的间接影响以及可归因于补充服务的直接影响。我们进一步询问，通识教育和职业培训是否相互促进，并且产生的联合影响大于两个单独途径的总和。此外，我们考察了所有工作队中心每个因果效应的异质性。本文介绍了不仅用于定义，识别和估计总体平均值，而且还用于定义这些因果关系的现场差异的概念和方法。我们的分析程序结合了一系列加权策略，以增强结果的内部和外部有效性，并评估对可能违反识别假设的敏感性。