An American Macroeconomic Picture: Supply and Demand Shocks in the Frequency Domain
用频域方法分析美国数据，发现供给冲击长期影响经济活动，需求冲击则否；两者都是经济周期波动的重要来源，但供给冲击主要驱动消费，需求冲击主要驱动投资。
We provide a few new empirical facts that theoretical models should feature in order to be consistent with the data. (i) There are two classes of shocks: demand and supply. Supply shocks have long-run effects on economic activity; demand shocks do not. (ii) Both supply and demand shocks are important sources of business cycles' fluctuations. (iii) Supply shocks are the primary driver for consumption fluctuations, demand shocks for investment. (iv) The demand shock is closely related to the credit spread, while the supply shock is essentially a news shock. The results are obtained using a novel frequency domain method.