Karl Pearson and the Origin of Kurtosis

Although the kurtosis index proposed by Karl Pearson in 1905 is introduced in statistical textbooks at all levels, the measure is not easily interpreted and has been a subject of considerable debate. In this study, the theoretical development of kurtosis is surveyed from a historical perspective of Pearson's work on evolution. It surprisingly emerges that there was no emphasis in Pearson's papers on kurtosis as measuring (in part) tail heaviness. However, it is found that Pearson used to frequently adjust the formalisation of kurtosis depending on his changing needs. This complex development partly explains the confusion that would surround kurtosis in subsequent literature. Our conclusion is that most misunderstandings arise from improper use of the kurtosis coefficient outside the Pearson system of frequency curves.     

Overlapping operations in material requirements planning

Material requirements planning (MRP) is a planning and information system that has widespread application in discrete-parts manufacturing. The purpose of this article is to introduce ideas that can improve the flow of material through complex manufacturing systems operating under MRP, and that can increase the applicability of MRP within diverse manufacturing environments.MRP models the flow of material by assuming that items flow from work station to work station in the same batches that are used in production. That is, once work starts on a batch of a certain item at a certain work station, the entire batch will be produced before any part of the batch will be transported to the next work station on its routing plan. Clearly, efficiency can be increased if some parallelism can be introduced. The form of parallelism investigated here is overlapping operations.Overlapping operations occurs when the transportation of partial batches to a downstream work station is allowed while work proceeds to complete the batch at the upstream work station. The potential efficiencies to be gained are the following:

• Reduced work-in-process inventory

• Reduced floor space requirements

• Reduced size of transfer vehicles

Additional costs may accrue through additional cost of transportation of partial batches and through additional costs of control.Some MRP software vendors provide the data processing capability for overlapping operations. However, the user is given little or no guidance on overlapping percentages or amounts. It is our intent to provide a simple, robust technique to MRP users who would like to overlap operations and gain some or all of the above efficiencies.An optimal lot-sizing technique is derived by considering a generic two work station segment of a manufacturing system. Under the assumptions of constant demand and identical production rates, a cost function that considers setup costs, inventory holding costs and transportation costs is derived. This cost function is minimized subject to the constraint that the production batch is an integer multiple of the transfer batch. We solve for the optimal production batch, the optimal transfer batch, and the integer number relating them. Solutions are obtained as closed form, easy to-evaluate formulas.By introducing more parallelism, overlapping operations can reduce lead time. However, this will not happen without modification of MRP logic to accommodate such reduced lead time. We derive a formula that shows how a significant lead time compression can easily be obtained and implemented in MRP.We consider an example to illustrate the application of the technique on typical data from the electronics industry. The outcome showed a cost savings of approximately 22.5% over the standard MRP approach.Overlapping operations allows the applicability of MRP to an increasing number of situations that are not modeled faithfully by conventional MRP logic. Three such situations that occur often are the following:

• Limited size of transfer vehicles dictate that several transfers should be planned.

• Lead time requirements prohibit nonoverlapped operations.

Our analysis suggests how to accommodate these difficult practical situations into MRP.Overlapping operations in material requirements planning provides an enhancement that allows wider applicability, shortened lead times, and lower total costs. It may be applied selectively to any two work stations where it is deemed appropriate. Due to the structure of the cost function, it is possible to make the transfer lot-sizing decisions independent of the production lot-sizing decisions. Therefore, significant improvements can be made through overlapping with minimum disruption to the existing MRP system machinery. It is our conviction that overlapping operations is an important concept that can and will impact MRP. We suggest the approach presented here as a systematic way to implement overlapping.     

Market clearing and derivative pricing

Summary. We develop a method of assigning unique prices to derivative securities, including options, in the continuous-time finance model developed in Raimondo (2001). In contrast with the martingale method of valuing options, which cannot distinguish among infinitely many possible option pricing processes for a given underlying securities price process when markets are dynamically incomplete, our option prices are uniquely determined in equilibrium in closed form as a function of the underlying economic data.Received: 14 April 2003, Revised: 7 January 2004, JEL Classification Numbers: G13, D52.This paper is dedicated to Birgit Grodal, whose strength and character we greatly admire. We are very grateful to Darrell Duffie, Steve Evans, Botond Koszegi, Roger Purves, Jacob Sagi, Chris Shannon, Bill Zame and an anonymous refereee for very helpful discussions and comments. The work of both authors was supported by Grant SES-9710424, and Andersons work was supported by Grant SES-0214164, from the National Science Foundation.     

The right way to be fired.

Nearly all of us will lose our jobs sometime, but is there a right way to be terminated? What differentiates fired employees who make the best of their situations from those who do not? One answer is mind-set. Many workers unconsciously hold a "tenure mind-set," believing in the promise of employment security. By contrast, other workers hold an "assignment mentality," seeing each job as one in a series of impermanent, career-building stepping-stones. Most corporate board members and CEOs have this latter mind-set and consider their executives to be filling terminal assignments; people who possess this mentality usually rebound swiftly when fired. But when employees who hold a tenure mind-set are suddenly fired or laid off, the authors say, they can fall into three common traps. Executives who have overidentified with their jobs and feel indispensable to their organizations get caught in the "lost identity" trap; they react to termination with anger and bitterness. In the "lost family" trap, employees possess tight-knit, emotional bonds with coworkers. When terminated, they feel betrayed and rejected. And finally, some introverted executives fall into the "lost ego" trap; they quietly retreat without negotiating fair termination packages and may settle for less satisfying work the next time around. To prepare for the eventuality of termination, the authors suggest that executives adopt the assignment mind-set at all times. They should keep their social networks alive, include a termination clause in employment contracts, and consider hiring an agent. If warning signs warrant, they might even volunteer to be terminated. By assuming control over the way they are fired, people can gain control over their careers.     

The Financial Milieu of the IASB and AASB

This paper considers the implications of the convergence of the accounting standards of the International Accounting Standards Board with those of the Australian Accounting Standard Board. Australia seems well placed to comply with the international accounting standards in 2005, but not quite in the way the boards would have us imagine. While actively seeking funds from large multinational corporations and elite accounting firms, the AASB is dominated by stakeholder groups with what are described as "corefinancial" and "partial-financial" interests. This financial milieu may offer cosy deals for the key stakeholders, but does little in the way of civic responsibilities and accounting service for the wider public .     

Making judgment calls. The ultimate act of leadership

According to the traditional view, judgment is an event: You make a decision and then move on. Yet Tichy, of the University of Michigan's Ross School of Business, and Bennis, of the University of Southern California's Marshall School of Business, found that good leadership judgment occurs not in a single moment but throughout a process. From their research into the complex phenomenon of leadership judgment, the authors also found that most important judgment calls reside in one of three domains: people, strategy, and crisis. Understanding the essence of leadership judgment is crucial. A leader's calls determine an organization's success or failure and deliver the verdict on his or her career. The first phase of the judgment process is preparation--identifying and framing the issue that demands a decision and aligning and mobilizing key stakeholders. Second is the call itself, And third is acting on the call, learning and adjusting along the way. Good leaders use a "story line"--an articulation of a company's identity, direction, and values--to inform their actions throughout the judgment process. Boeing CEO Jim McNerney, for instance, focused on a story line of Boeing as a world-class competitor and ethical leader to make a judgment call that launched the company's recovery from a string of ethical crises. Good leaders also take advantage of "redo loops" throughout the process, reconsidering the parameters of the decision, relabeling the problem, and redefining the goal in a way that more and more people can accept. Procter & Gamble's A.G. Lafley and Best Buy's Brad Anderson have both used redo loops--in preparation and execution, respectively--to strengthen not only support for their calls but also the outcomes.     

Pseudo empirical likelihood method in the presence of missing data

In this paper, we propose an estimator for the population mean when some observations on the study and auxiliary variables are missing from the sample. The proposed estimator is valid for any unequal probability sampling design, and is based upon the pseudo empirical likelihood method. The proposed estimator is compared with other estimators in a simulation study.     

Developing holistic leaders: Four domains for leadership development and practice

Leadership development and practice have traditionally been quite narrow, with a decided focus on the analytical realm of leadership. However, the contemporary climate of corporate scandal and resultant loss of societal confidence, coupled with the evolving demands, needs, and expectations of employees, point to the potential need for a more holistic approach to leadership. Thus, this article proposes how management education and leadership development programs can develop holistic leaders that are adept at operating in the analytical, conceptual, emotional, and spiritual domains of leadership practice. An integrated model for holistic leadership development and practice that addresses all four of these domains is proposed, and grounded in both established and emerging leadership development theory. Additionally, a leadership development classification scheme is proposed based on classroom, job, and organizational contexts.