Optimal 2n-p fractional factorial designs for dispersion effects under a location-diapersion model

We consider main effects models for 2-level experiments that also include. Parameters characterizing potential dispersion effects due to specified factors. One special case is considered. In this case only a single specified factor is responsible for the dispersion effects. We determine the connection between alias relations and Optimality of a design for estimation of dispersion effects in the class of regu!ar fractional Y - P factorial designs of resolution III or higher. This rmectioil heips US identify those designs that are A-optimal for estimating dispersion effects by a suitable choice of defining contrasts. in particuiar, we show that an increase in efficiency with respect to dispersion effects is accompanied by a loss iii efficiency for estimating the location effects. In practice, one mmt thcrcfcre accept a trade& between the efficiencies associated with estirnates of location effects and dispersion effects.     

Why Do Men and Women Challenge Gender Discrimination in the Workplace? The Role of Group Status and In-group Identification in Predicting Pathways to Collective Action

Group status and group identification were hypothesized to moderate the predictors of collective action to challenge gender discrimination against women. Higher identifiers were expected to respond to the inequality through the lens of their in-group's interests. Among highly identified women, collective action was predicted by appraisals of illegitimacy and feelings of anger, suggesting that they felt a sense of solidarity with the victims and experienced the justice violation as personally relevant. In contrast, higher identification with the high-status group should reflect more investment in the advantaged in-group, relative to the interests of the victimized out-group members. Thus, among highly identified men, collective action intentions were predicted by perceiving the inequality as pervasive (i.e., not limited to a few cases) and feelings of sympathy for victims. This suggests that highly identified men did not experience the inequality as self-relevant until they saw it as too widespread to be ignored. In contrast, men and women with lower gender group identification demonstrated more similar pathways to collective action, where sympathy was the main predictor. Theoretical and practical implications are discussed.     

Moments of the quartic assignment statistic with an application to multiple regression

We present the first three exact moments of the symmetric quartic assignment statistic. Efficient computational formulas have been derived to overcome severe difficulties in third moment calculations. Two examples illustrate applications of the quartic assignment statistic: evaluation of significant “clustering” or “mixing”; and distribution-free tests for equality of several planar regression models. This article extends previous results on the cubic assignment statistic in Iyer and Vecchia (1989).     

Effect of Quality Management Systems and Total Quality Management on Productivity Before and After: Empirical Evidence from the Indian Auto Component Industry

We study the linkages between firm‐level quality initiatives such as quality management systems (QMS) and total quality management (TQM) and output productivity in the Indian auto component industry. We use externally validated quality certification and quality awards as proxies for QMS and TQM, respectively, as it is difficult to directly measure the QMS and TQM efforts of firms. We use an unbalanced panel of 220 firms and a balanced panel of 73 firms from the Indian auto component industry over the period 1993–2006 to study these links. Both parametric as well as non‐parametric approaches are used, as appropriate, to measure the rate of change in productivity and the impact of quality initiatives on productivity change during this period. We determine the proportion of productivity resulting from technical change and relative efficiency change, thus providing insights into the structure of productivity improvements. We find that TQM efforts resulted in a high rate of productivity change (11%) in the award‐winning firms after the award. On the other hand, pre‐certification productivity change due to QMS was 5% and post‐certification change was 3.6%. In the periods prior to certification, productivity change was driven mainly by technical change; whereas the source of productivity change after certification is mixed. However, prior to awards, productivity change was driven mainly by relative efficiency change, whereas post‐award productivity change was due to technical change. The results suggest that management focus on attaining certification did generate conceptual learning (linked to technical change) during the period leading to certification, but these effects were not significant after certification. The results also suggest that the TQM programs generated significant productivity gains in the long run, although setting the associated systems in place did not result in significant productivity change prior to winning awards. Thus, the study provides direct but nuanced evidence linking quality certification as well as the adoption of TQM programs to the associated conceptual and operational learning processes and their impact on the change in productivity.     

Introduction to Special Issue on POM Research on Emerging Markets

This special issue presents production and operations management research papers from emerging markets worldwide, focusing on their unique contexts, institutions and markets. Collectively, they offer insights into the unique operations management strategies and practices that firms face in emerging markets. The magnitude and pace of change is staggering. As a result, execution and managing growth in these emerging markets represents both huge operational and supply chain risks, and simultaneously vast opportunities. We are confident that these papers stimulate new operations management research while highlighting the effective use of different research methodologies. We welcome you to enjoy this special issue of POMS. We express our deep gratitude to editorial team for their support. We especially wish to thank the authors for their contributions to this special issue.     

A comparison of confidence regions and designs in estimation of a ratio

A computer simulation is performed to compare confidence regions arising from Fie1ler's theorem and approximate large sample intervals in estimating the point of extremum in quadratic regression. In addition, two designs, one of which is motivated by optimal design theory, are compared. These comparisons are made by examining the confidence level and accuracy of the regions, as well as the concentration of the standard point estimator, in a variety of settings. The results have implications for the more general problem of estimating a ratio of linear combinations in the general linear model.     

Exact distribution-free tests for equality of several linear models

Exact tests for the equality of several linear models are developed using permutation techniques. Two cases of the linear model, characterized by either stochastic or nonstochastic predictors, are considered: the linear regression model (LRM) and the general linear model (GLM). A general class of test statistics using the volume of simplexes as the basic unit of analysis is proposed for this problem. The resulting class of statistics is shown to be a natural generalization of the multi-response permutation procedure (MRPP) test statistics which have been shown to comprise many of the statistics used in both parametric and nonparametric analysis of the standard g—sample problem. In the LRM case, exact moments of all orders are derived for the permutation distribution of any test statistic in the general class. Moment-based approximation of significance levels is shown to be computationally feasible in the simple LRM.     

Balanced e-optimal designs of resolution III for the 2×3 series

We consider the problem of constructing designs which are E-optimal in the class of all balanced resolution III designs for the 2^m×3ⁿ series. The inverse of the information matrix for general resolution III balanced 2^m×3ⁿ designs is obtained. Optimal designs are constructed for the cases (m,n)=(3, 1), (4, 1), (2, 2) and (3, 2) for various numbers of runs in the practical range.     

Remembering the impossible possibility: Kierkegaard and human capital

Kierkegaard is classified as an existentialist. The irony of course is if he were authentically existential, then he would escape any categorisation. Rather than reading Kierkegaard as yet one more item on the shelves of the history of philosophy, why not read him as though he were relevant to our lives? Our argument is that modern capitalism has taken a subjective turn, and therefore reading Kierkegaard is as timely as ever. This isn’t a matter of constructing a politics out his texts but applying it to our lives. The modern subjective form of capital is human capital as was already diagnosed by Foucault in his prophetic lectures on bio-politics. At the heart of human capital is the ideology of the subject as a form of investment. We want to show how Kierkegaard’s own account of subjectivity resists this appropriation of the self by capital through a new ontology of subjectivity. At the heart of this ontology is a reversal of Aristotle. It is not the actual that determines the possible, but the possible the actual.