In a recent article in the American Economic Review, Tatyana Deryugina and David Molitor (DM) analyzed the effect of Hurricane Katrina on the mortality of elderly and disabled residents of New Orleans. The authors concluded that Hurricane Katrina improved the eight-year survival rate of elderly and disabled residents of New Orleans by 3% and that most of this decline in mortality was due to declines in mortality among those who moved to places with lower mortality. In this article, I provide a critical assessment of the evidence provided by DM to support their conclusions. There are three main problems. First, DM generally fail to account for the fact that people of different ages, races or sex will have different probabilities of dying as time goes by, and when they do allow for this, results change markedly. Second, DM do not account for the fact that residents in New Orleans are likely to be selected non-randomly on the basis of health because of the relatively high mortality rate in New Orleans compared to the rest of the country. Third, there is considerable evidence that among those who moved from New Orleans, the destination chosen was non-random. Finally, DM never directly assessed changes in mortality of those who moved, or stayed, in New Orleans before and after Hurricane Katrina. These problems lead me to conclude that the evidence presented by DM does not support their inferences.
翻译:在《美国经济评论》最近的一篇文章中,Tatyana Deryugina和David Molitor(DM)分析了卡特里娜飓风对新奥尔良老年和残疾居民死亡率的影响,作者的结论是,卡特里娜飓风使新奥尔良老年和残疾居民的八年存活率提高了3%,而死亡率的下降大部分是由于那些迁移到死亡率较低的地方的人的死亡率下降。在本篇文章中,我对DM提供的证据进行了批判性评估,以支持他们的结论。有三大问题。首先,DM通常没有说明,随着时间流逝,不同年龄、种族或性别的人的死亡概率会有所不同,结果也会明显改变。第二,DM没有说明,新奥尔良居民由于新奥尔良的死亡率高于国内其他地区而可能被非随意挑选。第三,有相当多的证据表明,在从新奥尔良迁移的人中,所选择的目的地是非随机的。最后,DM从未直接评估过新奥尔良的死亡率变化,在飓风之后,没有直接评估过新奥尔良的死亡率。