In continuous trading, ruin problems are important for several reasons. ln the first part of the paper a test criterion for bankruptcy is developed. In the present framework one implicitly assumes the investor's wealth to be different from zero, otherwise the model is not well-defined. It is of...

The problem of determining optimal portfolio rules is considered. Prices are allowed to be stochastic processes of a fairly general nature, expressible as stochastic integrals with respect to semimartingales. The set of stochastic differential equations assumed to describe the price behaviour...

This article presents a valuation model of futures contracts and derivatives on such contracts, when the underlying delivery value is an insurance index, which follows a stochastic process containing jumps of random claim sizes at random time points of accident occurrence. Applications are made...

We consider a situation where relative prices of assets may change continuously and also have discrete jumps at random time points. The problem is the one of portfolio optimization. If the utility function used is the logarithm, we first argue that an optimal investment plan exists. Secondly, we...

The value of an insurance company mainly depends on the premiums received in each underwriting period, the probability distribution of the accumulated claims against the company, the equity capital, and the risk-adjusted rate of return determined by the market. We analyze how the value of the...

In this paper we present a partial economic equilibrium model of the labor market in which we maximize the workers' expected discounted utility level, while implying a zero expected profit for the firms.The model we use for the labor market takes into consideration transitions between the...