A MULTINOMIAL APPROXIMATION FOR AMERICAN OPTION PRICES IN LÉVY PROCESS MODELS

This paper gives a tree-based method for pricing American options in models where the stock price follows a general exponential Lévy process. A multinomial model for approximating the stock price process, which can be viewed as generalizing the binomial model of Cox, Ross, and Rubinstein (1979) for geometric Brownian motion, is developed. Under mild conditions, it is proved that the stock price process and the prices of American-type options on the stock, calculated from the multinomial model, converge to the corresponding prices under the continuous time Lévy process model. Explicit illustrations are given for the variance gamma model and the normal inverse Gaussian process when the option is an American put, but the procedure is applicable to a much wider class of derivatives including some path-dependent options. Our approach overcomes some practical difficulties that have previously been encountered when the Lévy process has infinite activity.     

What Kind of Voice Do Loyal Employees Use?

This study helps clarify mixed support for Hirschman's exit–voice–loyalty framework by arguing that loyalty, or feelings of attachment to the organization, and voice are not one–dimensional constructs. Based on data gathered from a survey of employees working with a large Canadian utility organization, employees feeling attached through an affective, emotional bond are found less likely to use representative voice but more likely to use direct voice, while those attached for rational, calculated reasons are more likely to use representative voice. Employees feeling attached for either reason are found less likely to exit. Implications for theory, research, and policy are discussed.     

DETERMINANTS OF GOODWILL AMORTIZATION PERIOD

This study investigates whether economic consequences have an effect on the length of the period over which goodwill is amortized. It finds that there is a significant relationship between the size of the firm and the length of the amortization period. It also finds, when the only firms included in the sample are those reporting debt covenant restrictions dependent in part on goodwill accounting, evidence that the length of the amortization period for goodwill is related to the firm's leverage.     

Competition and structural change in Eastern Europe

Widely publicized reform programs for East Europe which emphasize rapid privatization are questioned on the grounds that structural changes to assure workable competition take precedence and will take years. A mix of deconcentrated state, cooperative, worker-owned, private, and foreignowned business can be workable. Import competition and antitrust legislation have auxiliary roles.     

A comparison of several approximations to the power function of the likelihood ratio test in covariance structure analysis*

In this paper we compare alternative asymptotic approximations to the power of the likelihood ratio test used in covariance structure analysis for testing the fit of a model. Alternative expressions for the noncentrality parameter (ncp) lead to different approximations to the power function. It appears that for alternative covariance matrices close to the null hypothesis, the alternative ncp's lead to similar values, while for alternative covariance matrices far from H_o the different expressions for the ncp can conflict substantively. Monte Carlo evidence shows that the ncp proposed in Satorra and Saris (1985) gives the most accurate power approximations.     

Nea presidential address, 1993: Why black economists?

This article looks, with humor, at the role of black economists in academia and in the economics profession.     

Estimating nonlinear time-series models using simulated vector autoregressions

This paper develops two new methods for conducting formal statistical inference in nonlinear dynamic economic models. The two methods require very little analytical tractability, relying instead on numerical simulation of the model's dynamic behaviour. Although one of the estimators is asymptotically more efficient than the other, a Monte Carlo study shows that, for a specific application, the less efficient estimator has smaller mean squared error in samples of the size typically encountered in macroeconomics. The estimator with superior small sample performance is used to estimate the parameters of a real business cycle model using observed US time-series data.     

An interview with Rhonda Anderson. Interview by Connie R. Curran

Nurse executives working in a hospital system experience varied and challenging opportunities to enhance the quality of patient care as well as the success of their professional careers. In this interview, Rhonda Anderson, MPA, RN, CNAA, discusses the hospital system, the managed care environment, and the importance of developing nurse managers.