Estimation of a non-invertible moving average process: The case of overdifferencing

The effect of differencing all of the variables in a properly specified regression equation is examined. Excessive use of the difference transformation induces a non-invertible moving average (MA) process in the disturbances of the transformed regression. Monte Carlo techniques are used to examine the effects of overdifferencing on the efficiency of regression parameter estimates, inferences based on these estimates, and tests for overdifferenccing based on the estimator of the MA parameter for the disturbances of the differences regression. Overall, the problem of overdifferencing is not serious if careful attention is paid to the properties of the disturbances of regression equations.     

Some brief notes on the “unfinished business” of qualitative inquiry

The paper argues that there are a variety of implicit issues in qualitative inquiry that need to be addressed if the area is to develop in some normal science sense. This unfinished business is concerned with a deeper investigation of basic terms that are now simply taken for granted, such as theme and pattern. It also includes the need to develop rules which will assist in making and justifying how qualitative interpretations are made from the implicit processes of inference. Specific suggestions are made for accomplishing these issues.     

Do norms of decision-making styles,organizational design and management affect performance of Japanese firms? an exploratory study of medium and large firms

The success and resilience of Japanese firms have led many scholars and practitioners to theorize and speculate about the impact of what they have termed the 'Japanese management style' upon performance. There have been few studies that have attempted to explore empirically the links between the way Japanese firms organize, manage and decide, and their performance. This paper investigates the association between norms of decision-making style, organizational design and management, and some measures of firm performance. The empirical pattern of norms was assessed on the basis of responses of a random sample (N = 349) of Japanese managers. The study demonstrates that while there appears to be no support for the proposition that certain norms universally affect performance, in some sectors the impacts of norms on decision-making style, organizational design and management may be significant. The study concludes with the implications for theory building of this empirical exploration.     

Mokken scale analysis for polychotomous items: theory,a computer program and an empirical application

This paper contains three subjects. First, an extension of Mokken's nonparametric item response models from dichotomous items to items with two or more ordered answer categories is proposed. Second, a computer program to analyze multicategory item scores is presented. This program is called MSP. The analyses by means of MSP are based on the multicategory extension of Mokken's theory. Finally, an application of MSP to empirical multicategory test data is presented in order to illuminate its possibilities.     

Robustness to the unavailability of data in block designs

We present general results for finding or boundingt _maxB , the maximum number of arbitrary whole blocks of observations which can be removed from a block design, and still leave all of the elementary treatment contrasts estimable. The block sizes may be larger than the number of treatments. The results are applied to BBDs, reinforced BIBDs and BBDs, BTIBDs, and a series of variance balanced incomplete block designs with two block sizes. Also given for most of these designs, are results fort _max, the maximum number of arbitrary, scattered observations that can become unavailable, and still leave all of the elementary treatment contrasts estimable.The work was undertaken while Dr. Whittinghill was visiting Ohio State University, and supported by a grant from the Natural Sciences Division, Colby College, Waterville, Maine.     

The impact of capacity expansion on the market value of the firm

This paper empirically investigates the impact of capacity expansion decisions on the market value of the firm. Event study methodology is used to estimate the abnormal change in stock prices around capacity expansion decision announcements. On the day of the announcement, the magnitude of the price change is abnormally high, evidenced by a significantly positive mean standardized square of the abnormal change (Beaver's U-statistic). We also analyze factors that we could affect the direction and magnitude of the abnormal change in the stock prices. We find that the change in price on the day of the announcement is positively and significantly related to the real growth rate of the industry, and negatively and significantly related to the variability of demand. A negative relationship between the price change and industry capacity utilization is also found which can have important implications for companies which follow the wait-and-see approach to capacity expansion decisions. We also find management ownership to be a significant predictor in explaining stock price changes around these announcements.     

A comparison of approximately optimal stratification given proportional allocation with other methods of stratification and allocation

Summary In this article, we shall present an approximately optimal method for constructing stratum boundary points when the sample is allocated proportionally. The method is based on an equal partitioning of the cumulative off ^1/3, wheref is the distribution of the stratification variable. We show that in many practical situations this technique compares favourably with approximately optimal stratification and allocation methods previously suggested.

---

Zusammenfassung In diesem Artikel stellen wir eine annähernd optimale Methode zur Festlegung von Stratabegrenzungspunkten dar, die für proportional angeordnete Samples gilt. Die Methode basiert auf einer gleichen Einteilung derf ^1/3-Kummulation, wobeif die Verteilung der Stratifikations-variablen darstellt. Wir zeigen, daß diese Technik in vielen praktischen Fällen gegenüber den bisher vorgeschlagenen Methoden zur optimalen Stratifikation und Zuordnung nicht schlecht abschneidet.

     

Finding a lasting cure for U.S. health care

In "Making Competition in Health Care Work" (July-August 1994), Elizabeth Olmsted Teisberg, Michael E. Porter, and Gregory B. Brown ask a question that has been absent from the national debate on health care reform: How can the United States achieve sustained cost reductions while at the same time maintaining quality of care? The authors argue that innovation driven by rigorous competition is the key to successful reform. A lasting cure for health care in the United States should include four basic elements: corrected incentives to spur productive competition, universal insurance to secure economic efficiency, relevant information to ensure meaningful choice, and innovation to guarantee dynamic improvement. In this issue's Perspectives section, eleven experts examine the current state of the health care system and offer their views on the shape that reform should take. Some excerpts: "On the road to innovation, let us not forget to develop the tools that allow physicians, payers, and patients to make better decisions." I. Steven Udvarhelyi; "Health care is not a product or service that can be standardized, packaged, marketed, or adequately judged by consumers according to quality and price." Arnold S. Relman; "Just as antitrust laws are the wise restraints that make competition free in other sectors of the economy, so the right kind of managed competition can work well in health care." Edward M. Kennedy "Biomedical research should be considered primarily an investment in the national economic well-being with additional humanitarian benefits." Elizabeth Marincola.     

When an executive defects

The news that one of the company's senior managers is leaving comes as a complete surprise to Paul Simmonds, CEO of Kinsington Textiles, Inc. Ned Carpenter, KTI's vice president of operations for three years, writes in his resignation letter than he is leaving for a better opportunity. Simmonds soon learns that Carpenter's new job is at Daltex, one of KTI's main rivals in the intensely competitive carpet industry. Hiring Carpenter had helped Simmonds establish his reputation as a topnotch manager. Carpenter came to KTI with lots of ideas and put his enthusiasm to good use. Three years into a five-year change program, Carpenter had turned KTI's operations from one of the worst in the industry to one of the best. He also had helped develop and plan the upcoming launch of a new fiber coating--KTI's first breakthrough in years. In this fictitious case study, Simmonds, along with the company's counsel and vice president of human resources, must figure out how much and what sort of damage control they need. What are they going to tell the company's employees and the media? Should they immediately replace Carpenter with John Brady, the second-in-command of operations? What if Carpenter is taking KTI employees--and strategic information--with him to Daltex? Should Simmonds ask all his managers to sign noncompete agreements-something Carpenter was never asked to do? Should KTI sue Carpenter? Five experts offer advice about communicating with KTI's employees, the media, and Carpenter himself, and about protecting the company's confidential information.