SHORT‐MATURITY OPTIONS AND JUMP MEMORY

We investigate jump memory using an extensive database of short‐term S&P 500 index options. Jump memory refers to the attenuation of the implied jump intensity and magnitude parameters following a crash event. We use a genetic algorithm to obtain a time series of implied parameter estimates and posit behavioral and rational explanations for parameter attenuation following a crash event. We find that a nested form of the jump‐diffusion model sharpens the remaining parameter estimates and has a negligible effect on pricing accuracy.     

The Multilevel Approach to Repeated Measures for Complete and Incomplete Data

Repeated measurements often are analyzed by multivariate analysis of variance (MANOVA). An alternative approach is provided by multilevel analysis, also called the hierarchical linear model (HLM), which makes use of random coefficient models. This paper is a tutorial which indicates that the HLM can be specified in many different ways, corresponding to different sets of assumptions about the covariance matrix of the repeated measurements. The possible assumptions range from the very restrictive compound symmetry model to the unrestricted multivariate model. Thus, the HLM can be used to steer a useful middle road between the two traditional methods for analyzing repeated measurements. Another important advantage of the multilevel approach to analyzing repeated measures is the fact that it can be easily used also if the data are incomplete. Thus it provides a way to achieve a fully multivariate analysis of repeated measures with incomplete data. This revised version was published online in June 2006 with corrections to the Cover Date.     

Positive Accounting Theory as a Lakatosian Research Programme

‘Positive accounting theory’ fails to meet Popper's falsificationist criteria for scientific inquiry. This paper argues, however, that Lakatos' ‘methodology of scientific research programmes’ is superior to Popper's falsificationist methodology, and that ‘positive accounting research’ does meet Lakatos' criteria for ‘scientific' status. Within Lakatos’ philosophy of science, however, this claim does not necessarily represent an endorsement of positive accounting theory.