Unemployment Rate Dynamics and Persistent Unemployment under Rational Expectations
构建了一个失业率动态模型，通过搜索动态与库存调整的相互作用解释持续性周期性失业，强调劳动力异质性（高流动与低流动群体）对失业波动的影响，实证表明复苏期低流动个体比例上升导致就业概率下降、复苏缓慢。
This paper develops a model of unemployment rate dynamics that provides an explanation of persistent cyclical unemployment that does not involve persistent expectational errors or other nonoptimizing behavior. Our results are based on the interaction of search dynamics and inventory adjustments. An important element in these dynamics appears to be heterogeneity in the labor force which can be characterized as consisting of a relatively small group of high turnover individuals who comprise the bulk of normal unemployment and a larger group of low turnover individuals who dominate movements in cyclical unemployment. Our empirical results provide support for this theory as we demonstrate that the appropriately measured probability of becoming employed during a recovery falls relative to normal because of the unusually high proportion of low turnover individuals who have lost permanent jobs. As aresult, recovery is much slower than is indicated by normal relationships although each individual is searching optimally.