Are Output Fluctuations Transitory?
质疑产出波动是暂时偏离趋势的传统观点，基于美国战后季度数据发现，实际GNP的意外变动会长期改变预测，表明波动可能具有持久性。
According to the conventional view of the business cycle, fluctuations in output represent temporary deviations from trend. The purpose of this paper is to question this conventional view. If fluctuations in output are dominated by temporary deviations from the natural rate of output, then an unexpected change in output today should not substantially change one's forecast of output in, say, five or ten years. Our examination of quarterly postwar United States data leads us to be skeptical about this implication. The data suggest that an unexpected change in real GNP of 1 percent should change one's forecast by over 1 percent over a long horizon.