The role of observed and unobserved heterogeneity in the duration of unemployment
研究工人可观察和不可观察特征如何解释失业总持续时间的变化，发现未观察到的异质性是失业风险持续时间依赖性的主要原因，且长期失业者驱动了失业平均持续时间的周期性和低频变化。
Summary This paper studies the degree to which observable and unobservable worker characteristics account for the variation in the aggregate duration of unemployment. I model the distribution of unobserved worker heterogeneity as time varying to capture the interaction of latent attributes with changes in labor‐market conditions. Unobserved heterogeneity is the main explanation for the duration dependence of unemployment hazards. Both cyclical and low‐frequency variations in the mean duration of unemployment are mainly driven by one subgroup: workers who, for unobserved reasons, stay unemployed for a long time. In contrast, changes in the composition of observable characteristics of workers have negligible effects.