Cyclical Unemployment: Sectoral Shifts or Aggregate Disturbances?
证明，在经验满足的条件下，传统单因素商业周期模型也会产生部门就业增长率离散度与失业率的正相关；通过职位空缺率数据区分部门转移与总体需求解释，发现离散度与招聘广告量负相关，支持总体需求解释。
Recent work by David Lilien has argued that the positive correlation between the dispersion of employment growth rates across sectors (a) and the unemployment rate implies that sectoral shifts in labor demand are responsible for a substantial fraction of cyclical variation in unemployment. This paper demonstrates that, under empirically satisfied conditions, traditional single-factor business-cycle models will produce a positive correlation between (sigma) and the unemployment rate. Information on the job vacancy rate permits one to distinguish between a pure sectoral shift and a pure aggregate demand interpretation of this positive correlation. The finding that a and the volume of help wanted advertising (a job vacancy proxy) are negatively related supports an aggregate demand interpretation.