Additive and Multiplicative Uncertainty Revisited: What Explains the Contrasting Biases?

above the certainty level while for additive uncertainty the price should be lower than the certainty level. This note gives an intuitive explanation for the result after first presenting a parsimonious review of the two models. We also discuss which, if either, of the two models is more realistic. Received December 14, 2001; revised version received July 16, 2002 Published online: April 30, 2003 We thank referees for helpful comments. Ciaran Driver would like to acknowledge the research facilities from ANU, Canberra for their help in writing this paper.     

Pricing Options on an Asset with Bernoulli Jump-Diffusion Returns

The price movements of certain assets can be modeled by stochastic processes that combine continuous diffusion with discrete jumps. This paper compares values of options on assets with no jumps, jumps of fixed size, and jumps drawn from a lognormal distribution. It is shown that not only the magnitude but also the direction of the mispricing of the Black-Scholes model relative to jump models can vary with the distribution family of the jump component. This paper also discusses a methodology for the numerical valuation, via a backward induction algorithm, of American options on a jump-diffusion asset whose early exercise may be profitable. These cannot, in general, be accurately priced using analytic models. The procedure has the further advantage of being easily adaptable to nonanalytic, empirical distributions of period returns and to nonstationarity in the underlying diffusion process.     

The 1986 U.K. Insolvency and Company Directors' Disqualification Acts: An evaluation of their impacts upon small firm financing decisions

This paper examines the potential impact of the 1986 U.K. Insolvency and Company Directors' Disqualification Acts on small firm financing decisions. With the aid of a simplified Black and Scholes (1973) option model of financing decisions, the paper illustrates how the 1986 legislation reduces the incentives for owner-managers to gamble with creditor claims, particularly in situations of financial distress, by making them personally liable for unmet claims and/or by disqualifying them from holding office for a fixed period. For instance, example 3 in the paper shows the conflict that could result from the owner-manager reducing his/her opening equity position and it further argues how the legislation should act to alleviate the situation. It remains, however, an empirical question as to whether this reduction in creditors' exposure to the risk of uncompensated wealth transfers will ultimately result in a significantly greater number of company liquidations and disqualifications, particularly during a prolonged economic downturn, or an improved/less costly supply of finance to small firms.     

Action Teams That Work

A growing awareness of workplace hazards and identification of airborne contaminants, coupled with a changing safety and health regulatory environment, created an unexpected demand for new and innovative respirators in the early 1980s. 3M's Occupational Health and Environmental Safety Division broke new ground by taking the team concept further than ever before in the company. The division's Action Teams successfully designed, built and introduced products in less than half the time it would have taken previously. Robert Hershock, Charles Cowman and Douglas Peters describe how 3M learned important lessons about team selection, training, performance and motivation, the importance of project sponsors, and the role of middle management.     

Further Ambiguity When Performance Is Measured by the Security Market Line

This paper employs the optimality conditions for expected utility and mean-variance portfolio problems to examine the ambiguities associated with the security market line criterion both at a point in time and through time. At a point in time, we show that the security market line criterion can be irrelevant, even in meanvariance economies. In a multiperiod setting, we show that the analysis of performance based on portfolio choice is inconsistent with the analysis based on return generating models. Empirical work suggests that the inconsistency can lead to dramatically different estimates of a security's required return.