Government policies are frequently used to promote productivity. Some policies are designed to enhance production technology, while others are meant to improve production efficiency. An important issue to consider when designing and evaluating policies is whether a mediator is required or effective in achieving the desired final outcome. To better understand and evaluate the policies, we propose a new stochastic frontier model with a treatment status and a mediator, both of which are allowed to be endogenous. The model allows us to decompose the total program (treatment) effect into technology and efficiency components, and to investigate whether the effect is derived directly from the program or indirectly through a particular mediator. Supplementary materials for this article are available online.

政府政策经常被用来提高生产力。一些政策旨在增强生产技术，而另一些政策旨在提高生产效率。在设计和评估政策时要考虑的一个重要问题是，是否需要调解人或有效地实现预期的最终结果。为了更好地理解和评估政策，我们提出了一种新的具有治疗状态和介体的随机边界模型，这两种模型都可以是内生的。该模型使我们能够将整个程序（处理）效果分解为技术和效率组件，并研究效果是直接从程序中导出还是通过特定介体间接导出。可在线获得本文的补充材料。