Background: Ongoing mortality trends affect the distribution of age at death, typically described by parametric models. Cohort effects can markedly perturb the distribution and reduce the fit of such models, and this needs to be specifically taken into account. Objective: This study examines the integration of cohort effects in a three-component parametric model for the age-at-death distribution, applying it to data with significant cohort effects. Methods: We employed a mixture model with a half-normal and two skew-normal components, adapted to a Bayesian framework to include multiplicative cohort effects. The model was applied to data from five Italian regions, with cohort effects estimated for the 1915–1925 cohorts. Results: Incorporating cohort effects significantly improved the model’s fit. A notable finding of the comprehensive model is the shift in Italy from premature to middle-age mortality components over time. Our results also demonstrate the tendency for mortality structures to spatially homogenize over time in Italy. Conclusions: The study underscores the importance of including cohort effects in mortality models in order to provide a more detailed picture of mortality trends. Contribution: This work introduces a novel application of a Bayesian mixture model with cohort effects, offering enhanced tools for demographic analysis and new insights into the evolution of mortality components in Italy. This approach is general but fully formalized and hence it can be readily used for demographic studies in other regions as well.

中文翻译：

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具有队列效应的死亡年龄贝叶斯模型（作者：Matteo Dimai、Marek Brabec）


背景：持续的死亡率趋势会影响死亡年龄的分布，通常由参数模型描述。同期群效应会显著扰乱分布并降低此类模型的拟合度，这需要特别考虑。目的： 本研究检查了队列效应在死亡年龄分布的三分量参数模型中的整合，并将其应用于具有显着队列效应的数据。方法：我们采用了一个具有半正态和两个偏态正态分量的混合模型，适用于贝叶斯框架以包含乘法队列效应。该模型应用于来自意大利五个地区的数据，并估计了 1915-1925 年同期群的同期群效应。结果：纳入队列效应显著提高了模型的拟合度。综合模型的一个显著发现是，随着时间的推移，意大利的死亡率成分从早产死亡率转变为中年死亡率。我们的结果还表明，意大利的死亡率结构随着时间的推移在空间上趋于同质化。结论： 该研究强调了在死亡率模型中包括队列效应的重要性，以便提供更详细的死亡率趋势图。贡献： 这项工作介绍了具有队列效应的贝叶斯混合模型的新应用，为人口统计分析提供了增强的工具，并为意大利死亡率成分的演变提供了新的见解。这种方法是通用的，但完全形式化，因此它也可以很容易地用于其他地区的人口研究。