论文标题
在差异分析中构建更紧密匹配的对照组：其对历史与组偏差相互作用的影响
Constructing a More Closely Matched Control Group in a Difference-in-Differences Analysis: Its Effect on History Interacting with Group Bias
论文作者
论文摘要
与对照组不同的对照组的差异分析很容易受到对这些组影响不同影响的历史事件的偏见。通过将整个对照组的子集与治疗组匹配的子集构建更紧密匹配的对照组可能会导致偏差更少。我们在模拟研究中研究了这种现象。我们使用差异分析分析研究了山顶去除挖掘（MRM）对死亡率的影响，该分析利用了1990年《清洁空气法》修订后MRM的增加。对于MRM对死亡率的影响的差异分析，我们构建了一个更紧密匹配的对照组，并找到了一个95 \％的置信区间，其中包含很大的不良影响，没有效果和小小的有益作用。
Difference-in-differences analysis with a control group that differs considerably from a treated group is vulnerable to bias from historical events that have different effects on the groups. Constructing a more closely matched control group by matching a subset of the overall control group to the treated group may result in less bias. We study this phenomenon in simulation studies. We study the effect of mountaintop removal mining (MRM) on mortality using a difference-in-differences analysis that makes use of the increase in MRM following the 1990 Clean Air Act Amendments. For a difference-in-differences analysis of the effect of MRM on mortality, we constructed a more closely matched control group and found a 95\% confidence interval that contains substantial adverse effects along with no effect and small beneficial effects.
