Resolving the Mixed Models Controversy

Two standard mixed models with interactions are discussed. When each is viewed in the context of superpopulation models, the mixed models controversy is resolved. The tests suggested by the expected mean squares under the constrained-parameters model are correct for testing the main effects and interactions under both the unconstrained-and constrained-parameters models.     

Confidence Bounds for Multiplicative Comparisons

Statements that are inherently multiplicative have historically been justified using ratios of random variables. Although recent work on ratios has extended the classical theory to produce confidence bounds conditioned on a positive denominator, this current article offers a novel perspective that eliminates the need for such a condition. Although seemingly trivial, this new perspective leads to improved lower confidence bounds to support multiplicative statements. This perspective is also more satisfying as it allows comparisons that are inherently multiplicative in nature to be properly analyzed as such.     

Robust Methods of Building Regression Models—An Application to thè Housing Sector

This article studies robustification strategies for the linear model in the presence of outliers. The advantages of an internal analysis of the robustness of least squares for a given sample are pointed out. The application of this methodology is illustrated by building an explicit model of the determinants of rental housing values in the Madrid Metropolitan Area.     

Whither the virtuous cycle? Past and future trends in black-white inequality in educational attainment

The inequality in the relative years of education between blacks and whites has diminished dramatically over the 20th century. One possible explanation for this convergence is a virtuous cycle of parents passing on educational advantage, from one generation to the next, leading to an overall educational upgrading. In this paper we test the virtuous cycle hypothesis by estimating the three way interaction of cohort, race, and family background. We find that the convergence in educational attainment between blacks and whites over the past century was driven by processes unrelated to family background.     

Differentiated leader–member exchange,justice climate,and performance: Main and interactive effects

Leaders form different quality leader–member exchange (LMX) relationships with their subordinates. This variable treatment termed LMX differentiation can have negative effects on individuals' behavior and attitudes. In this study, we examined the cross-level main effect of justice climate on task performance and the moderating role of justice climate on the relationship between LMX differentiation and task performance. We tested these two hypotheses using a field study of 90 subordinates nested under 27 supervisors. Procedural justice climate, not distributive justice climate, was found to positively influence subordinate task performance. Further, distributive justice climate, not procedural justice climate, was found to moderate the LMX differentiation–task performance relationship; such that the relationship was positive when distributive justice climate was high and negative when distributive justice climate was low. Findings and future directions are discussed.     

Effects of Leadership Style,Creativity Technique and Personal Initiative on Employee Creativity

Transformational leadership is assumed to enhance employees' creativity. However, results of meta‐analytic research on the relations between transformational leadership and creativity have fallen short of expectations. The authors argue that, besides leadership style, the creativity technique that a leader employs is an important means of stimulating employees' creativity. In addition, it is assumed that leadership styles and creativity techniques may have different effects, depending on the measure of creativity output (quantitative vs qualitative). Therefore, in an experimental setting, the effects of different creativity techniques (provocation technique vs brainwriting) and leadership styles (transformational vs transactional) on both quantitative and qualitative creativity were examined. Results showed that transformational leadership and provocation technique led to higher levels of qualitative creativity than transactional leadership and brainwriting, respectively. Conversely, transactional leadership and brainwriting were more effective for quantitative creativity. The additional benefit of the provocation technique in qualitative creativity was found to be higher in the transactional leadership condition than in the transformational leadership condition. Moreover, personal initiative made a significant and independent contribution to both qualitative and quantitative creativity. Implications for practice and future research are discussed.