Measuring Business Cycles: A Modern Perspective
回顾了商业周期研究中两个被忽视的特征：多个经济序列的协同变动以及扩张与收缩期的不同行为，并综述了动态因子模型和非线性模型的最新进展，最后通过实证分析尝试将两者结合，以评估其对商业周期动态统计描述的价值。
In the first half of this century, special attention was given to two features of the business cycle: (1) the comovement of many individual economic series and (2) the different behavior of the economy during expansions and contractions. Both of these attributes were ignored in many subsequent business cycle models, which were often linear representations of a single macroeconomic aggregate. However, recent theoretical and empirical research has revived interest in each attribute separately. Notably, dynamic factor models have been used to obtain a single common factor from a set of macroeconomic variables, and nonlinear models have been used to describe the regime-switching nature of aggregate output. We survey these two strands of research and then provide some suggestive empirical analysis in an effort to unite the two literatures and to assess their usefulness in a statistical characterization of business- cycle dynamics.