The Real Response to Uncertainty Shocks: The Risk Premium Channel.

The article focuses on the interaction between uncertainty shocks and time-varying risk aversion (RA) and its effects on macroeconomic dynamics and asset pricing. Empirical evidence shows that positive uncertainty shocks lead to larger and more prolonged declines in output, consumption, investment, and equity prices when RA is high, a phenomenon termed the "risk premium channel." This channel is further supported by cross-sectional stock return patterns, where conditional exposures to uncertainty and RA explain significant risk premia, unlike unconditional exposures. The authors develop a New-Keynesian dynamic stochastic general equilibrium model incorporating Epstein–Zin recursive preferences with external habit to generate endogenous time-varying RA, successfully replicating empirical findings. The model highlights that habit-induced countercyclical RA amplifies uncertainty shocks by increasing precautionary savings and equity risk premia, causing firms to reduce investment and production, thereby deepening economic downturns. These results underscore the importance of accounting for state-dependent risk aversion in understanding the macroeconomic impact of uncertainty and in designing monetary and fiscal policies.