Another 'futile quest'? A simulation study of Yang and Land's Hierarchical Age-Period-Cohort model
Another 'futile quest'? A simulation study of Yang and Land's Hierarchical Age-Period-Cohort model
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DOI：
10.4054/demres.2014.30.11
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发表时间：
2014-02-04
影响因子：
2.1
通讯作者：
Jones, Kelvyn
中科院分区：
文献类型：
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作者：
Bell, Andrew;Jones, Kelvyn
虽然有些人认为，解决年龄段队列（APC），识别问题。是不可能的，许多方法的解决方案已被提出，包括杨和土地的分层APC（HAPC）模型：一个多层次的模型，考虑期间和队列作为交叉分类的情况下，其中个人existing.Objective评估的假设，由HAPC模型，在这种情况下，它做和不工作。模拟情景评估（a）数据生成过程中的群组趋势的影响（与仅随机变化相比），和（B）分组队列结果该模型仅在以下两种情况下有效：（a）我们可以假设没有线性关系，（B）我们控制模型固定部分中的任何队列趋势，并假设不存在周期趋势，或者（c）我们以这样一种方式对队列进行分组，即它们与（未知）DGP中的分组完全匹配。否则，该模型可以任意重新分配APC的影响，从根本上影响interpretation.CONCLUSIONS由于APC分析的目的往往是为了确定存在的时期和/或队列的趋势，因为我们很少有坚实的（如果有的话）理论关于队列分组，有几种情况下，该模型实现了杨和土地声称它可以。这些结果对几项使用HAPC模型的已发表研究的结果提出了质疑。然而，模型的结构仍然是一个概念上的进步，当我们可以假设DGP没有周期趋势时，它是有用的。
BACKGROUND Whilst some argue that a solution to the age-period-cohort (APC), identification problem. is impossible, numerous methodological solutions have been proposed, including Yang and Land's Hierarchical-APC (HAPC) model: a multilevel model considering periods and cohorts as cross-classified contexts in which individuals exist.OBJECTIVE To assess the assumptions made by the HAPC model, and the situations in which it does and does not work.METHODS Simulation study. Simulation scenarios assess the effect of (a) cohort trends in the Data Generating Process (DGP) (compared to only random variation), and (b) grouping cohorts (in both DGP and fitted model).RESULTS The model only works if either (a) we can assume that there are no linear (or non-linear) trends in periods or cohorts, (b) we control any cohort trend in the model's fixed part and assume there is no period trend, or (c) we group cohorts in such a way that they exactly match the groupings in the (unknown) DGP. Otherwise, the model can arbitrarily reapportion APC effects, radically impacting interpretation.CONCLUSIONS Since the purpose of APC analysis is often to ascertain the presence of period and/or cohort trends, and since we rarely have solid (if any) theory regarding cohort groupings, there are few circumstances in which this model achieves what Yang and Land claim it can. The results bring into question findings of several published studies using the HAPC model. However, the structure of the model remains a conceptual advance that is useful when we can assume the DGP has no period trends.