Empirically, earnings at the start or end of earnings spells are lower and more volatile than in the interior of earnings histories, reflecting mainly the effects of working less than the full year. Ignoring these properties leads to a mismeasurement of the permanent and transitory shock variances and induces the large and widely documented divergence in the estimates of those variances based on fitting the earnings moments in levels or growth rates. Accounting for these effects enables more accurate analysis using quantitative models with permanent and transitory earnings risk and improves empirical estimates of consumption insurance against permanent earnings shocks.

中文翻译：

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改进收入动态的衡量

根据经验，与盈利历史内部相比，盈利期开始或结束时的盈利较低且波动较大，主要反映了工作时间少于全年的影响。忽略这些属性会导致对永久性和暂时性冲击方差的错误测量，并导致基于将收益时刻拟合为水平或增长率的这些方差的估计存在巨大且广泛记录的差异。考虑到这些影响，可以使用具有永久性和暂时性收入风险的定量模型进行更准确的分析，并改进针对永久性收入冲击的消费保险的经验估计。