Behind the steady march of progress toward longer life expectancy in many low‐mortality countries, there have been setbacks even before the Covid‐19 pandemic. In this paper, we use an exploratory approach to describe the temporal structure, age patterns, and geographic aspects of life expectancy reversals. We find that drops in life expectancy are often followed by larger than average improvements, which tells us that most reversals are transitory with little long‐term influence. The age structure of mortality decline when life expectancy falls is tilted toward older ages, a pattern that is quite different from the general pattern of mortality improvement. Geographic analysis shows that mortality reversals are correlated across neighboring countries like Italy and France, or Canada and the United States. These findings are consistent with contagious disease and weather being important causes of life expectancy reversals. We conclude with a discussion of implications for formal modeling and forecasting of mortality to accommodate these patterns that violate some standard assumptions.

中文翻译：

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低死亡率人群的预期寿命逆转

许多低死亡率国家在延长预期寿命方面稳步前进，但在 Covid-19 大流行之前就已经出现了挫折。在本文中，我们使用探索性方法来描述预期寿命逆转的时间结构、年龄模式和地理方面。我们发现，预期寿命下降之后往往会出现高于平均水平的改善，这告诉我们大多数逆转都是暂时的，几乎没有长期影响。当预期寿命下降时，死亡率下降的年龄结构向老年倾斜，这种模式与死亡率改善的一般模式有很大不同。地理分析显示，意大利和法国、加拿大和美国等邻国的死亡率逆转是相关的。这些发现与传染病和天气是预期寿命逆转的重要原因一致。最后，我们讨论了正式建模和死亡率预测的影响，以适应这些违反某些标准假设的模式。