A valuation model for firms with stochastic earnings

In this paper, a model is set up for valuing a firm with stochastic earnings. It is assumed that the earnings of the considered firm follow a time-varying mean reverting stochastic process. It is shown that the value of the firm satisfies a boundary value problem of a second-order partial differential equation, which can be solved numerically. Special cases are discussed. Analytic solution is found for one special case. Moreover it is shown that the analytic solution is consistent with a previous result obtained by other researchers.stochastic earnings, firm valuation, debt valuation

The Arbitrage Efficiency of the Nikkei 225 Options Market: A Put-Call Parity Analysis

This paper is concerned with arbitrage efficiency of the Nikkei index option contracts traded on the Osaka Securities Exchange ( OSE) within the put-call parity (PCP) framework. A thorough ex post analysis is first carried out. The results reveal a modest number of violations with 2.74 percent of the sample breaching the PCP equation and an average arbitrage profit of 22.61 index points for OSE member firms during the sample period (2003?05). Ex ante tests are then conducted whereby ex post profitable arbitrage strategies, signified by the matched put and call contracts, are executed with lags of one minute and three minutes. The ex ante results reveal that the number of profitable arbitrage opportunities and the average profit are both reduced significantly with an execution lag. In addition, regression analysis is used to provide further evidence about the PCP and arbitrage profitability. Overall, there is no strong evidence found against the efficiency of the Nikkei 225 options market, although arbitrage opportunities do exist occasionally.Put-call parity; Market efficiency; Nikkei 225 options

A single-period model and some empirical evidences for optimal asset allocation with value-at-risk constraints

In this paper, we consider the optimal asset allocation problems under VaR constraints. It is shown that the separation property holds to a certain extent. The optimal allocation of funds in risky assets is dependent on the distribution of the returns of risky assets and the VaR level, but independent of the acceptable loss ratio; the amount to be borrowed or lent at the risk free rate depends on the acceptable loss ratio. A general asset allocation model under VaR constraints is derived. As an application of our model, we address the optimal asset allocation between two categories of assets—bonds and stocks. Interesting empirical results are obtained for the US, Australia and the UK. The empirical results show that the mechanism of asset allocation under VaR constraints is fundamentally different from the classical mean-variance approach. The empirical results appear to support our model and demonstrate the potential usefulness of our approach.Value at Risk, optimal asset allocation, separation property, empirical