We provide necessary and sufficient conditions on an individual's expected utility function under which any zero-mean idiosyncratic risk increases cautiousness (the derivative of the reciprocal of the absolute risk aversion), which is the key determinant for this individual's demand for options...

We provide a necessary and a sufficient condition on an individual's expected utility function under which any zero-mean idiosyncratic risk increases cautiousness (the derivative of the reciprocal of the absolute risk aversion), which is the key determinant for this individual's demand for...

We study the representative consumer's risk attitude and efficient risk-sharing rules in a single-period, single-good economy in which consumers have homogeneous probabilistic beliefs but heterogeneous risk attitudes. We prove that if all consumers have convex absolute risk tolerance, so must...

We study option pricing and hedging with uncertainty about a Black-Scholes reference model which is dynamically recalibrated to the market price of a liquidly traded vanilla option. For dynamic trading in the underlying asset and this vanilla option, delta-vega hedging is asymptotically optimal...

We study the pricing and hedging of derivative securities with uncertainty about the volatility of the underlying asset. Rather than taking all models from a prespecified class equally seriously, we penalise less plausible ones based on their "distance" to a reference local volatility model. In...

While humans often care about sunk investment, animals are not subject to this sort of sunk cost behavior or "Concorde fallacy". This paper investigates a simple two stage decision problem under uncertainty. At the second stage, subjects can commit the Concorde fallacy by sticking to the first...

Human behavior, rational or irrational one, influences one of the most complex markets worldwide: the insurance market. In most situations, insurance markets are not competitive and risk neutral insurers negotiate under asymmetric information with actors who exhibit risk aversion. In this paper...

We propose a single evolutionary explanation for the origin of several behaviors that have been observed in organisms ranging from ants to human subjects, including risk-sensitive foraging, risk aversion, loss aversion, probability matching, randomization, and diversification. Given an initial...

This paper studies a class of robust mean-variance portfolio selection problems with state-dependent risk aversion. Model uncertainty, in the sense of considering alternative dominated models, is introduced to the problem to reflect the investor's ambiguity aversion. To characterize the robust...

This paper develops a tractable dynamic model of competition between two risk-averse portfolio managers who attempt to outperform each other by trading in different stocks, reflecting asset specialization. We characterize explicitly the unique Nash equilibrium portfolio policies, and show that a...