Stochastic Volatility for Lévy Processes

Three processes reflecting persistence of volatility are initially formulated by evaluating three Lévy processes at a time change given by the integral of a mean-reverting square root process. The model for the mean-reverting time change is then generalized to include non-Gaussian models that are solutions to Ornstein-Uhlenbeck equations driven by one-sided discontinuous Lévy processes permitting correlation with the stock. Positive stock price processes are obtained by exponentiating and mean correcting these processes, or alternatively by stochastically exponentiating these processes. The characteristic functions for the log price can be used to yield option prices via the fast Fourier transform. In general mean-corrected exponentiation performs better than employing the stochastic exponential. It is observed that the mean-corrected exponential model is not a martingale in the filtration in which it is originally defined. This leads us to formulate and investigate the important property of martingale marginals where we seek martingales in altered filtrations consistent with the one-dimensional marginal distributions of the level of the process at each future date.     

AN ECONOMETRIC ANALYSIS OF EQUITY COSTS AND RISK PREMIUMS IN THE ELECTRIC UTILITY INDUSTRY: 1971–1985

This paper develops a varying parameter econometric model that estimates the cost of equity of individual utility firms from 1971 to 1985. The equity costs estimated in this framework can be analyzed in terms of their statistical precision. The paper also examines, theoretically and empirically, the relationship between the econometric estimates of the equity risk premiums and the risk-free interest rates. The data do not support the hypothesis that risk premiums are independent of interest rates. Also, the relationship appears to vary over time. These results invalidate the risk premium approach in which equity costs are estimated by adding a constant, historical average risk premium to the prevailing interest rates.     

Option Pricing With V. G. Martingale Components1

European call options are priced when the uncertainty driving the stock price follows the V. G. stochastic process (Madan and Seneta 1990). the incomplete markets equilibrium change of measure is approximated and identified using the log return mean, variance, and kurtosis. an exact equilibrium interpretation is also provided, allowing inference about relative risk aversion coefficients from option prices. Relative to Black-Scholes, V. G. option values are higher, particularly so for out of the money options with long maturity on stocks with high means, low variances, and high kurtosis.     

SIMPLE PROCESSES AND THE PRICING AND HEDGING OF CLIQUETS

For data on market prices for 246 cliquets we consider pricing these exotic options using a relatively simple path space. The path space is subsequently stressed to market implied stress levels as well as stress levels predicted from contract characteristics. An additive process transitioning from a Sato process to a Levy process is formulated and estimated on vanilla options. Ask prices constructed from predicted stress levels are observed to have an in sample correlation of 92% with market prices. Interestingly, it is observed that capped cash flows have negative stress levels while uncapped products have positive stress levels. We illustrate the effect of hedging cliquet liabilities using call options as hedging assets permitting a 10% reduction in ask prices.     

A tale of two volatilities

We show that there are two distinct ways to make volatility stochastic that are differentiated by their consequences for skewness. Most models in the literature have adopted the relatively tractable methodology of using stochastic time changes to engineer stochastic volatility. Unfortunately, this is also the one that can conflict with the relationship occasionally observed in markets between volatility and skewness. Research enhancing the tractability of the second approach to stochastic volatility based on scaling is called for.     

Simultaneous determination of product attributes and prices, and production processes in product-line design

Global competition, rapid changes in technology, and market fragmentation have resulted in shorter product life cycles. In order to remain viable, it is increasingly important for firms to introduce new products frequently. Product design is a complex process that involves coordination of activities among several functional disciplines within the company as well as the customers and the suppliers. Traditionally, the information flow among the various product development stages has been sequential. However, there is increasing evidence to suggest that an integrated approach that considers several stages simultaneously may be superior.This paper provides a decision support tool for implementing such an integrated approach. On the basis of given customer preferences, the paper presents a model for determining the number of new products to be introduced, the exact specifications of these products, and the production processes for efficiently delivering these specifications. These decisions are made in an integrated manner by simultaneously considering the interaction among the various choice variables. A decomposition-based solution procedure is developed that iterates between the product design and process selection decisions while maintaining an effective link between them.In addition to understanding the economic value of adopting the integrated approach to product design, the paper discusses how the proposed model can be used effectively to perform sensitivity analysis with respect to some of the important decision variables.     

Job autonomy, trust in leadership, and continuous improvement: An empirical study in health care

This research examines the influence of autonomy in day-to-day work on commitment of frontline employees to continuous improvement. Our hypothesized model links the job characteristics theory of work design that associates job autonomy with responsibility for outcomes, and the total quality management perspective that advocates empowering employees in order to generate commitment to continuous improvement. Further, as leadership is known to have a role in shaping job behaviors, and is considered important for the success of total quality management, the influence of trust in leadership on the relationship between job autonomy and commitment to continuous improvement is also examined. We test our hypotheses on data collected from individual employees working for an outpatient health care organization that is applying lean principles for managing and improving work processes. Based on our results, we present implications for organizations implementing continuous improvement initiatives such as lean, particularly in service environments such as health care.