Intuition and leading equilibrium models are at odds with the empirical evidence that expected returns are weakly related to volatility at the market level. This paper proposes a closed-form general equilibrium model, which connects the investors’ expectations of fundamentals with those...

We combine new developments in decision theory with a standard consumption-based asset-pricing framework. In our model the efficient market hypothesis is violated if and only if agentsÂ’ beliefs' express ambiguity about the stochastic process driving economic fundamentals. Asset price...