Ambiguity and learning about the equity premium can simultaneously explain the low fraction of financial wealth allocated to stocks over the life cycle and the stock market participation puzzle. Individuals are ambiguous about the size of the equity premium and are averse to this ambiguity,...

I develop a stochastic growth model with production where there is a hidden state governing productivity growth regimes, and the hidden state evolves according to a Markov chain. Economic agents learn about the hidden state and display ambiguity aversion in the spirit of Klibanoff et al. (2005)....

We examine risk taking when the bank's preferences exhibit smooth ambiguity aversion. Ambiguity is modeled by a second-order probability distribution that captures the bank's uncertainty about which of the subjective beliefs govern the financial asset return risk. Ambiguity preferences are...

We examine a production-based asset pricing model with an unobservable mean growth rate ollowing a two-state Markov chain and with an ambiguity averse representative agent. Our model requires a low coefficient of relative risk aversion to produce: (i) a high equity premium and volatile equity...

In a setting with information asymmetry and a tradable value-weighted market index, ambiguity averse investors hold undiversified portfolios, and assets have non-zero alphas. But when a passive fund offers the risk-adjusted market portfolio (RAMP) whose weights depend on information precisions...

We derive the equilibrium asset expected returns when there is ambiguity in asset expected returns, as well as ambiguity in asset return variances. In our model, ambiguity risk is systematic in nature and is non-diversifiable. Under regularity conditions, expected asset returns are linearly...

We confront the generalized recursive smooth ambiguity aversion preferences of Klibanoff, Marinacci, and Mukerji (2005, 2009) with data using Bayesian methods introduced by Gallant and McCulloch (2009) to close two existing gaps in the literature. First, we use macroeconomic and financial data...

We formulate a tractable continuous-time rational expectations model in which the agent is ambiguity averse and would like to robustify asset return specification. Ambiguity affects the portfolio rule and asset pricing both individually and collectively with risk. Independently existing...

We study optimal portfolio choice and equilibrium asset prices induced by alpha-maxmin expected utility (alpha-MEU) models. In the standard Ellsberg framework we prove that alpha-MEU preferences are equivalent to either maxmin, maxmax or subjective expected utility (SEU). We show how ambiguity...

In real world financial markets, dividend processes as well as fundamental values are governed by imprecision; neither the objective probabilities of returns nor the actual amounts of possible returns are known for certain. With a novel experimental approach, we analyze the impact of risk,...