Information Matrices for Non Full Rank Subsystems

Consider the standard linear model Y=X θ + ε. If the parameter of interest is a full rank subsystem K′θ of mean parameters, the associated information matrix can be defined via an extremal representation. For rank deficient subsystems, Pukelsheim (1993) introduced the notion of generalized information matrices that inherit many properties of the information matrices. However, this notion is not a direct extension of the full rank case in the sense that the definition of the generalized information matrix applied to full rank subsystems does not lead to the usual information matrix. In this paper, we propose a definition of the information matrix via an extremal representation that encompasses the full rank and the non-full rank cases. We also study its properties and show its links with the generalized information matrices.     

Optimal designs for a mixed interference model

This paper generalizes Kunert and Martin’s (Ann Stat 28:1728–1742, 2000) method for finding optimal designs under a fixed interference model, to find optimal designs under a mixed interference model. The results are based on the properties of information matrices in fixed and mixed models given in Markiewicz (J Stat Plan Inference 59:127–137, 1997). The method is applied to find a design which is optimal for any given variances of random neighbor effects. Research partially supported by the KBN Grant Number 5 P03A 041 21.     

Technical Analysis as a Rational Tool of Decision Making for Professional Traders

The psychological background of technical analysis usage is investigated to further explain the popularity and common usage of technical analysis as an investment decision tool. Attitudes toward technical analysis of professional futures market traders and neophyte investors, represented by finance students, were examined. Technical analysis is one of the most popular methods supporting investment decisions and it is much more popular among future market traders than among neophyte investors. The concept of processing information was used to explain this phenomenon. Neophyte investors are more experiential and intuition-driven while using technical analysis models, while futures market traders are more rationally driven. Technical analysis methods help professional traders on futures markets, which are less transparent than regulated stock markets, to process information; those methods are perceived by them as rational, cognitive tools supporting their decision making.     

Cross-sex relationships at work and the impact of gender stereotypes

Organizations pride themselves on their creation of rational structures based primarily on a male perspective of interaction. Workers are expected to set aside interpersonal behaviours that do not directly contribute to task performance. As more women enter management, norms concerning appropriate interpersonal relationships at work are undergoing strain. In addition, the phenomenon of mutual sexual attractions between co-workers is demanding attention. This study systematically describes attitudes, attributions and anticipated consequences of mutual sexual attractions at work. Findings suggest that gender stereotypes are significant factors in people's judgments of persons involved in sexual attractions at work.Irene Devine is currently professor and Director, School of Administration and Information Management, Ryerson Polytechnical Institute, Toronto. She was formerly Associate Dean, Faculty of Commerce and Administration, Concordia University, Montreal. Her research interests include organizational crisis, and women in organizations. She has recently co-authored a management textbook.Dorothy Markiewicz is currently Associate Professor, departments of Psychology and Applied Social Science, and Program Director, Centre for Human Relations and Community Studies, Concordia University, Montreal. She was formerly Chairperson. Applied Social Science. Her research interests include sex differences and stereotypes, adult development, and friendship.     

MODEL UNCERTAINTY AND EXCHANGE RATE VOLATILITY*

This article proposes an explanation for shifts in the volatility of exchange‐rate returns. Agents are uncertain about the true data generating model and deal with this uncertainty by making inference on the models and their parameters' approach, I call model learning. Model learning may lead agents to focus excessively on a subset of fundamental variables. Consequently, exchange‐rate volatility is determined by the dynamics of these fundamentals and changes as agents alter models. I investigate the empirical relevance of model learning and find that the change in volatility of GBP/USD in 1993 was triggered by a shift between models.     

Optimality and efficiency of circular neighbor balanced designs for correlated observations

The purpose of this paper is to apply the Kunert and Martins (2000b) method for finding optimal designs into the case of dependence. Using this method we study optimality of circular neighbor balanced designs at distances 1 and 2 under the one-dimensional interference model with errors correlated according to a circular autoregressive process. We determine the efficiency of binary designs for specified values of correlation coefficient, for which these designs are not optimal.Research partially supported by the KBN Grant Number 5 P03A 041 21.     

Playing a double game? Pursuing innovation through ambidexterity in an international acquisition program from the Arabian Gulf Region

Acquisitions represent a strategy for enhancing competitive responsiveness in the global management of technology and innovation. Even more than single and domestic acquisitions, cross‐border acquisition programs present opportunities for firms seeking to sustain innovation. Yet, scant attention has been paid to the innovation dynamics of pursuing multiple, international acquisitions. We remedy this gap by investigating a multinational logistics firm enacting a multi‐decade program of cross‐border, technology intensive acquisitions and achieving dual competencies in (1) innovation and ambidexterity, (2) the exploration and exploitation capabilities of ambidexterity, and (3) tight and loose integration approaches. We determine that the firm relied on contextual, temporal, and structural manifestations of ambidexterity in acquisition integration. Findings illuminate the processual nature of an international acquisition program and suggest how ambidexterity benefits the acquisition of both innovation and innovative capabilities, when a firm applies a portfolio of tight‐to‐loose integration approaches.     

The (mis)measurement of M&A performance—A systematic narrative literature review

This paper seeks to further the understanding of the variety of meanings M&A scholars attach to the label “M&A performance” by providing an alternative way to interpret the claimed inconsistency of M&A research findings. While many scholars contend that the problem stems from the multiplicity of M&A performance measures, we believe the problem rests in trying to compare different measures as if they were measuring the same feature of the organization. Through our narrative review of empirical research we analyze factors shaping the M&A – as well as the organizational – performance measurement process. The conclusion is that it is not possible to talk about M&A performance as if it was a universal construct.     

Universally optimal designs under mixed interference models with and without block effects

The literature on neighbor designs as introduced by Rees (Biometrics 23:779–791, 1967) is mainly devoted to construction methods, providing few results on their statistical properties, such as efficiency and optimality. A review of the available literature, with special emphasis on the optimality of neighbor designs under various fixed effects interference models, is given in Filipiak and Markiewicz (Commun Stat Theory Methods 46:1127–1143, 2017). The aim of this paper is to verify whether the designs presented by Filipiak and Markiewicz (2017) as universally optimal under fixed interference models are still universally optimal under models with random interference effects. Moreover, it is shown that for a specified covariance matrix of random interference effects, a universally optimal design under mixed interference models with block effects is universally optimal over a wider class of designs. In this paper the method presented by Filipiak and Markiewicz (Metrika 65:369–386, 2007) is extended and then applied to mixed interference models without or with block effects.