The Relative Importance of Aggregate and Sectoral Shocks and the Changing Nature of Economic Fluctuations
利用行业生产数据的成分分解，发现总体冲击对总产出波动的贡献从1967-1983年的约70%下降到1983年后的约30%；构建两部门模型表明，部门冲击相对重要性的上升能解释劳动生产率的顺周期性减弱等变化。
A principal components decomposition of sectoral IP data reveals that the contribution of aggregate shocks to the variance of aggregate output declined from about 70 percent in the period 1967–1983 to about 30 percent after 1983. We develop an “islands” model with two sectors and costly labor reallocation to investigate how this change in the relative importance of shocks alters business cycle moments. A version of the model with relatively more important sectoral shocks results in a sizeable decline in the cyclicality of labor productivity and is consistent with changes in several other business cycle moments observed in the data.