Pessimism, Disagreement, and Economic Fluctuations
研究发现经济衰退时家庭悲观情绪和意见分歧加剧，提出模糊性冲击驱动商业周期的理论，解释了实际变量与预期数据的联动。
Abstract The pessimistic bias and the cross-sectional dispersion of households’ subjective beliefs heighten during recessions. We provide empirical evidence for a dominant non-inflationary aggregate demand shock that accounts for the bulk of business-cycle fluctuations not only in real quantities but also in (1) pessimism—to what degree households are more pessimistic than the rational expectation benchmark and (2) disagreement—the cross-sectional dispersion of households’ beliefs. To rationalize the empirical findings, this paper develops a theory of ambiguity-driven business cycles, where the Bayesian formulation of the ambiguity shock can generate positive co-movements across real quantities together with counter-cyclical pessimism and disagreement within the real business-cycle framework. Our theory reproduces the salient features of the business cycles extended with survey data on households’ expectations. Quantitatively, the ambiguity shock alone accounts for a significant fraction of the business-cycle fluctuations in pessimism, disagreement, and real quantities.