Business Cycle Accounting
提出一种方法，通过测量效率、劳动、投资和政府消费四种楔子，并将其代入增长模型，来评估它们对美国经济波动的解释程度。研究发现效率和劳动楔子解释了几乎所有波动，投资楔子作用很小，政府消费楔子无作用。
We propose a simple method to help researchers develop quantitative models of economic fluctuations. The method rests on the insight that many models are equivalent to a prototype growth model with time-varying wedges that resemble productivity, labor and investment taxes, and government consumption. Wedges that correspond to these variables-efficiency, labor, investment, and government consumption wedges-are measured and then fed back into the model so as to assess the fraction of various fluctuations they account for. Applying this method to U.S. data for the Great Depression and the 1982 recession reveals that the efficiency and labor wedges together account for essentially all of the fluctuations; the investment wedge plays a decidedly tertiary role, and the government consumption wedge plays none. Analyses of the entire postwar period and alternative model specifications support these results. Models with frictions manifested primarily as investment wedges are thus not promising for the study of U.S. business cycles. Copyright The Econometric Society 2007.