In this paper we study the equilibrium in a heterogeneous economy with twogroups of investors. Over-confident experts incorrectly assume that their signalfor the drift of the dividend process is correlated with the true drift, butinterpret the signal otherwise perfectly. Rational laymen avoid...

Model mis-specification can cause substantial utility losses in portfolio planning.In this paper, we compare two approaches to cope with this problem,robust control and learning. We derive the optimal portfolio strategies and theutility losses due to model mis-specification. Surprisingly,...

We perform a general equilibrium analysis in a complete markets economy whenthe dividend follows a jump-diffusion process with stochastic volatility. Agents haveCRRA utility, but differ with respect to their degree of risk aversion. The keyoutput of our analysis is the structure of the...

In this paper we perform a general equilibrium analysis when the dividend followsa jump-diffusion process with stochastic volatility, where both the dividend itselfand its volatility can jump. We work in a complete markets economy and assumethat agents have CRRA utility, but can differ with...

Since trading cannot take place continuously, the optimal portfolio calculated ina continuous-time model cannot be held, but the investor has to implement thecontinuous-time strategy in discrete time. This leads to the question how severe theresulting discretization error is. We analyze this...

Variance contracts permit the trading of ’variance risk’, i.e. the risk that the realizedvariance of stock returns changes randomly over time. We discuss why investorsmight want to trade this type of risk, and why they might prefer a variance contractto standard calls and puts for this...

This paper deals with the superhedging of derivatives on incomplete markets, i.e.with portfolio strategies which generate payoffs at least as high as that of a givencontingent claim. The simplest solution to this problem is in many cases a staticsuperhedge, i.e. a buy-and-hold strategy...

The observed prices of out-of-the money put options seem too high given standardderivative pricing models. One possible explanation is a Peso problem: crashes (forwhich the payoff of a put is high) are taken into account for pricing, but are under-represented in the data sets used for empirical...

The vast majority of approaches to risk management, hedging, or portfolio planningassume that some model is given. However, under model risk, the true data gener-ating process is not known. The focus of this paper is on problems related to thehedging of derivative contracts. We explain the main...

In this paper we analyze an economy with two heterogeneous investors who both exhibit misspecified filtering models for the unobservable expected growth rate of the aggregated dividend. A key result of our analysis with respect to long-run investor survival is that there are degrees of model...