We provide a new theory of expectations-driven business cycles in which consumers' learning from prices dramatically alters the effects of aggregate shocks. Learning from prices causes changes in aggregate productivity to shift aggregate beliefs, generating positive price-quantity comovement....

We identify the main shock driving fluctuations in long‐horizon productivity expectations, consistent with theories of TFP news. The identified shock induces strong comovement patterns in output, consumption, investment, employment, and stock prices even though TFP does not change...

We show that a model with imperfectly forecastable changes in future productivity and an occasionally binding collateral constraint can match a set of stylized facts about "sudden stop" events. "Good" news about future productivity raises leverage during times of expansion, increasing the...

We provide a new theory of expectations-driven business cycles in which consumers' learning from prices dramatically alters the effects of aggregate shocks. Learning from prices causes changes in aggregate productivity to shift aggregate beliefs, generating positive price-quantity comovement....

The literature on belief-driven business cycles treats news and noise as distinct representations of agents' beliefs. We prove they are empirically the same. Our result lets us isolate the importance of purely belief-driven fluctuations. Using three prominent estimated models, we show that...