论文标题
使用熵平衡来减少差异差异模型的偏差
Reducing bias in difference-in-differences models using entropy balancing
论文作者
论文摘要
本文说明了当干预前结果趋势表明可能违反平行趋势假设时，在差异分析中使用熵平衡。我们描述了一组假设，在这些假设下，即使干预前的差异趋势趋势与干预前趋势的平衡干预和比较组也会导致一致的差异估计，即使干预前的结果趋势不相似。模拟结果验证了干预前结果的熵平衡趋势在不直接满足平行趋势假设时会消除偏见，因此可能使研究人员能够在更广泛的观察环境中使用比以前确认的更广泛的观察环境中的差异差异设计。
This paper illustrates the use of entropy balancing in difference-in-differences analyses when pre-intervention outcome trends suggest a possible violation of the parallel trends assumption. We describe a set of assumptions under which weighting to balance intervention and comparison groups on pre-intervention outcome trends leads to consistent difference-in-differences estimates even when pre-intervention outcome trends are not parallel. Simulated results verify that entropy balancing of pre-intervention outcomes trends can remove bias when the parallel trends assumption is not directly satisfied, and thus may enable researchers to use difference-in-differences designs in a wider range of observational settings than previously acknowledged.
