In multiple-task hidden-action models, the (mis-)allocation of effort may play an important role for benefit creation. Signals which capture this benefit and which are used in incentive schemes should thus not only be judged by the noise and the associated costs but also by the mis-allocation...

The market model of interest rates specifies simple forward or Libor rates as lognormaly distributed, their stochastic dynamics has a linear volatility function. This model is extended to quadratic volatility which is the product of a quadratic polynomial and a level-independent covariance...

The market model of interest rates specifies simple forward or Libor rates as lognormally distributed, their stochastic dynamics has a linear volatility function. In this paper, the model is extended to quadratic volatility functions which are the product of a quadratic polynomial and a...

The basic model of financial economics is the Samuelson model of geometric Brownian motion because of the celebrated Black-Scholes formula for pricing the call option. The asset's volatility is a linear function of the asset value and the model garantees positive asset prices. In this paper it...

It is well-known that Gaussian hedging strategies are robust in the sense that they always lead to a cost process of bounded variation and that a superhedge is possible if upper bounds on the volatility of the relevant processes are available, cf. El Karoui, Jeanblanc-Picque and Shreve (1998)...

The paper generalizes and refines the Fundamental Theorem of Asset Pricing of Dalang, Morton and Willinger in the following two respects: (a) the result is extended to a model with portfolio constraints; (b) versions of the no-arbitrage criterion based on the bang-bang principle in control...

In this paper, the effects of so-called model misspecification and the effects of dropping the assumption that continuous rebalancing is possible are examined. Strategies which are robust if applied continuously fail to be robust if applied in discrete time. Therefore, the hedging bias which...

Let S=(S_t), t=0,1,...,T (T being finite), be an adapted R^d-valued process. Each component process of S might be interpreted as the price process of a certain security. A trading strategy H=(H_t), t= 1,...,T, is a predictable R^d-valued process. A strategy H is called extreme if it represents a...

In this paper, the effects of so-called model misspecification and the effects of dropping the assumption that continuous rebalancing is possible are examined. Strategies which are robust if applied continuously fail to be robust if applied in discrete time. Therefore, the hedging bias which...