We consider portfolio selection under nonparametric alpha-maxmin ambiguity in the neighbourhood of a reference distribution. We show strict concavity of the portfolio problem under ambiguity aversion.Implied demand functions are nondifferentiable, resemble observed bid-ask spreads, and are...

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...

The propensity of households to invest in stocks is lower than implied by Expected Utility Theory. One explanation suggested in the literature is that stocks entail ambiguity and investors are ambiguity averse. We test this hypothesis, measuring participation using equity fund flows and...

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 propose an equilibrium model of asset prices in which agents learn about the mean and the volatility of the endowment process and differ in their concerns about parameter uncertainty. We show that, in equilibrium, following unexpected bad and good news about economic outcomes (i) uncertainty...