MODELS AND DESIGNS FOR EXPERIMENTS WITH MIXTURES

Properties such as the tensile strength of an alloy of. different metals and the freezing point of a mixture of liquid chemicals, depend on the proportions (by weight or volume) of the components present and not on the total amount of the mixture. In choosing a model to relate such a property to the proportions of the various components of the mixture, there arise intriguing difficulties due to the fact that proportions sum to unity. It is demonstrated how to construct models which allow for the possibility of inactive components (components that do not affect the property at all) or components with additive effects. The design of experiments to fit such models to data is then discussed with a view to determining whether a given component is inactive or has an additive effect. The optimal allocation of observations to simplex-lattice designs is considered for one of these models. The construction of D -optimal designs for these models is an open problem.     

Stability analysis using mixed models: A critique of tolerance interval methods and a probabilistic solution

Recently, tolerance interval approaches to the calculation of a shelf life of a drug product have been proposed in the literature. These address the belief that shelf life should be related to control of a certain proportion of batches being out of specification. We question the appropriateness of the tolerance interval approach. Our concerns relate to the computational challenges and practical interpretations of the method. We provide an alternative Bayesian approach, which directly controls the desired proportion of batches falling out of specification assuming a controlled manufacturing process. The approach has an intuitive interpretation and posterior distributions are straightforward to compute. If prior information on the fixed and random parameters is available, a Bayesian approach can provide additional benefits both to the company and the consumer. It also avoids many of the computational challenges with the tolerance interval methodology.     

Social Identification and Corporate Irresponsibility: A Model of Stakeholder Punitive Intentions

Scholars hypothesize that retaliations against corporate social irresponsibility (CSI) are more likely when observers share the social identity of the victims. We present a model that explains in‐group bias against irresponsibility and identify collective narcissism as a moderator of this effect. Experiment 1 demonstrates that the effect of identity on retaliations is mediated by the perceived similarity of the victims which reinforces feelings of sympathy towards the victims and anger towards the corporation. These emotions drive stakeholders’ attitudes and retaliations. Our study shows that appraisals of the victims of CSI are an important antecedent of stakeholders’ emotions and behavioural intentions. Our evidence also demonstrates that sympathy, an emotion neglected by past research in this area, has a unique effect on individuals’ reactions. Experiment 2 demonstrates that social identity biases in individual punitive intentions are moderated by individuals’ level of collective narcissism. Collective narcissists see out‐group victims as very dissimilar from the self, whereas individuals with low levels of collective narcissism do not differentiate between victims of CSI on the basis of their identity. We extend knowledge on stakeholders’ reactions to CSI and offer insights to organizations promoting campaigns against irresponsible behaviour or managing the fallout from cases of corporate irresponsibility.     

What Narrows the Stepgap? Closeness Between Parents and Adult (Step)Children in Germany

Using data from the German Family Panel (pairfam) based on 11,746 intergenerational family relationships, the present study examined differences in parental closeness across relations with multiple, coresidential, and non‐coresidential adolescent and adult children. Replicating previous research in a multilevel analysis across families, the authors found a strong positive effect of biological descent on closeness in comparison to adoptive and steprelations; this parental favoritism toward biological offspring was partly explained by selection via parental resources and attitudes. Supplemental within‐parent fixed effect analyses suggested that the relative disadvantage of stepchildren was offset by longer duration of the stepparent–stepchild relationship, lower household income, fewer children in the household, and high parental affirmation of familism.     

Beyond Social Constructionism: Critical Realism and Social Work

Summary Theories within the social and psychological sciences continueto shape social work practice. However, recent debates withinthese sciences on the shortcomings of ‘social constructionism’,and the attempt to overcome them through a critical realistposition, have so far failed to capture social work's attention.This paper provides a critical overview of these theoreticaldebates, highlighting the shortcomings of social constructionismfor social work. The critical realist challenge to social constructionism,as articulated by the British philosopher Roy Bhaskar, is consideredand its relevance to social work formulated in terms of a returnto ‘depth’ in practice.     

Enriching Absorptive Capacity through Social Interaction

Absorptive capacity is frequently highlighted as a key determinant of knowledge transfer within multinational enterprises. But how individual behaviour translates into absorptive capacity at the subsidiary level, and how this is contingent on subsidiaries' social context, remains under‐addressed. This not only limits our understanding of the relationship between individual‐ and organizational‐level absorptive capacity, but also hampers further research on potentially relevant managerial and organizational antecedents, and limits the implications we can draw for practitioners who seek to increase their organization's capacity to put new knowledge to use. To address this shortcoming we conduct an in‐depth comparative case study of a headquarters‐initiated knowledge transfer at two subsidiaries of the same multinational enterprise. The findings demonstrate that social interaction is a prerequisite for subsidiary absorptive capacity as it enables employees to participate in the transformation of new knowledge to the local context and the development of local applications. The findings also illustrate how organizational conditions at the subsidiary level can impact subsidiary absorptive capacity by enabling or constraining local interaction patterns. These insights contribute to the absorptive capacity literature by demonstrating the scale and scope of social interaction as a key link between individual‐ and organizational‐level absorptive capacity.     

A Hausman test for Brownian motion

New tests are proposed for the specification of the intraday price process of a risky asset, based on open, high, low, and close prices. Under the null of a Brownian process we derive two stochastically independent, unbiased volatility estimators. For a Hausman specification test we prove its equivalence with an F-test, consider its robustness against variation in drift and volatility, and analyze the power against an Ornstein–Uhlenbeck process, as well as a random walk with alternative distributions.