We consider dynamic sublinear expectations (i.e., time-consistent coherent risk measures) whose scenario sets consist of singular measures corresponding to a general form of volatility uncertainty. We derive a càdlàg nonlinear martingale which is also the value process of a superhedging...

In this paper we present a two period model, where the agent's preferences are described by prospect theory as proposed by Kahneman and Tversky. We solve for the agent's portfolio decision. Our findings are that the changes in portfolio weights depend crucially on the reference point and the...

We propose a simplified approach to mean-variance portfolio problems by changing their parametrisation from trading strategies to final positions. This allows us to treat, under a very mild no-arbitrage-type assumption, a whole range of quadratic optimisation problems by simple mathematical...

We show that the optimal asset allocation for an investor depends crucially on the theory with which the investor is modeled. For the same market data and the same client data different theories lead to different portfolios. The market data we consider is standard asset allocation data. The...

We compare asset allocations that are derived for cumulative prospect theory (CPT) based on two different methods: maximizing CPT along the mean {variance efficient frontier and maximizing CPT without this restriction. We find that with normally distributed returns, the difference between these...

Ambiguity aversion in dynamic models is motivated by the presence of unknown time-varying features, which agents do not understand and cannot theorize about. We analyze the consequences of this assumption for economic agents and model builders, who typically need to estimate a model, e.g., to...

Estimates of agents' risk aversion differ between market studies and experimental studies. We demonstrate that the estimates can be reconciled through consistent treatment of agents' tendency for narrow framing, regarding integration of background wealth as well as across risky outcomes: Risk...

This paper addresses the question of optimal currency exposure for a risk-and-ambiguity-avers international investor. A robust mean-variance model with smooth ambiguity preferences is used to derive the optimal currency exposure. In the theoretical part, we show that the sample-efficient...

Using properties of the cdf of a random variable defined as a saddle-type point of a real valued continuous stochastic process, we derive first-order asymptotic properties of tests for stochastic spanning w.r.t. a stochastic dominance relation. First, we define the concept of Markowitz...

We develop and implement methods for determining whether introducing new securities or relaxing investment constraints improves the investment opportunity set for prospect investors. We formulate a new testing procedure for prospect spanning for two nested portfolio sets based on subsampling and...