摘要：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 percent and that most of this decline in mortality was due to declines in mortality among those who moved to places with lower mortality. I provide a critical assessment of the evidence that DM provide 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 sexes 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 aged 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 compare changes in mortality of those who moved and those who stayed in a direct manner. These problems lead me to conclude that the evidence presented by DM does not support their inferences.
