Finie mixures of canonical fundamenal skew $$$$-disribuions

This paper introduces a finite mixture of canonical fundamental skew \(t\) (CFUST) distributions for a model-based approach to clustering where the clusters are asymmetric and possibly long-tailed (in: Lee and McLachlan, arXiv:1401.8182 [statME], 2014b). The family of CFUST distributions includes the restricted multivariate skew \(t\) and unrestricted multivariate skew \(t\) distributions as special cases. In recent years, a few versions of the multivariate skew \(t\) (MST) mixture model have been put forward, together with various EM-type algorithms for parameter estimation. These formulations adopted either a restricted or unrestricted characterization for their MST densities. In this paper, we examine a natural generalization of these developments, employing the CFUST distribution as the parametric family for the component distributions, and point out that the restricted and unrestricted characterizations can be unified under this general formulation. We show that an exact implementation of the EM algorithm can be achieved for the CFUST distribution and mixtures of this distribution, and present some new analytical results for a conditional expectation involved in the E-step.     

The Experience-Earnings Profile: Productivity-Augmenting or Purely Contractual? Evidence from the UK

We test the human capital interpretation of the experience-earnings profile. Does the upward sloping portion of the experience-earnings profile reflect on-the-job training which in turn causes the experience-productivity profile to slope upwards, or do purely contractual factors determine the nature of life-cycle earnings. Herein, we provide additional evidence on the relationship between productivity and earnings by examining earnings differentials in the UK academic labor market for economists. Using a test first suggested by Mincer, we find that the empirical results are consistent with human capital theory. We find that, although the positive relationship between earnings and experience persists when individual productivity measures are included in the salary equations for lecturers and senior lecturers, the positive relationship becomes statistically insignificant when the same productivity measures are included in the salary equations for professors. For lecturers and senior lecturers, the experience-salary profile properly reflects the structure of the national pay scale rather than variations in individual research productivity. At the professor level, where individual salaries are not determined by a pay scale, the data support the human capital explanation of the positive experience-earnings profile.

On approximations via convolution-defined mixture models

An often-cited fact regarding mixing or mixture distributions is that their density functions are able to approximate the density function of any unknown distribution to arbitrary degrees of accuracy, provided that the mixing or mixture distribution is sufficiently complex. This fact is often not made concrete. We investigate and review theorems that provide approximation bounds for mixing distributions. Connections between the approximation bounds of mixing distributions and estimation bounds for the maximum likelihood estimator of finite mixtures of location-scale distributions are reviewed.     

A preliminary look at relationships between married gay men and lesbians and their parents-in-law: Five case studies

With marriage between lesbians and between gays now legal in the United States, it is important to gain an understanding of how in-law relationships function for this population. Five case studies, part of a larger study of in-law relationships, are presented that help further knowledge of the potential obstacles that some couples may face in relation to their in-laws. Common experiences include relationships improving over time; struggling with acceptance; feeling closer to parents-in-law because other adult children or adult children-in-law have fallen out of favor; recognizing the significant role that the child-in-law’s spouse plays in the relationship between the child-in-law and the parent-in-law; understanding the role that the larger community plays; considering both parents-in-law as separate voices in the in-law dyad; and experiencing feelings of ambivalence that arise between family members. Practice implications for clinicians are included as are implications for future research.     

Transparency tested: The influence of message features on public perceptions of organizational transparency

The concept of transparency has been promoted within the public relations and business literature as both ethical and advantageous; however, the effectiveness of transparency is seldom empirically put to the test. In particular, the use of clarity, disclosure, and accuracy in organizational messages needs to be empirically examined. To this end, we conducted an online experiment using a 2 (high vs. low message transparency) x 2 (news story placed before or after an organizational statement) between-subjects design. Participants (n?=?357) perceived organizations as more transparent and credible when exposed to messages exhibiting greater levels of clarity, disclosure, and accuracy as opposed to messages that did not. Placement of an information anchor in the form of an objective news story before the organizational message increased the perceived organizational transparency when messages employed transparent design features and decreased the perceived organizational transparency when messages did not use these features. These results provide significant implications for practitioners attempting to convey organizational transparency at the tactical level through message features.     

The Nature of the Political Reconsidered

I present an immanent, and explanatory, critique of reflections on the nature of politics and of power within political science. I argue that these reflections are problematic, to the extent that they presuppose an actualist conception of the political, and that this is generated by an empiricist way of thinking on the one hand and a constructivist way of thinking on the other. I show how re‐defining politics, power, and the political on the basis of a dialectical critical realist ontology resolves these problems and, thereby, allows us to understand the conditions for social change and the relationship between the political and the economic. My argument has two, important implications: first, that the proposal that those who study politics professionally should celebrate philosophical diversity is dangerous–at least if it makes it difficult to sustain a distinct, emancipatory form of political inquiry; and, second, that the nature of social reality justifies the need both for specialized forms of inquiry, such as politics and economics, and integrative forms of inquiry, such as political economy.     

Do Some Students Need Special Protection From Research on Sex and Trauma? New Evidence for Young Adult Resilience in “Sensitive Topics” Research

Institutional review boards (IRBs) have expressed concerns that certain individuals or groups, such as participants who are younger, ethnic minorities, or who have certain psychological or personality traits, may be particularly distressed when participating in “sensitive topics” research. This study examined the effects of several demographic and individual difference factors (i.e., age, sex, ethnicity, religiosity, Big Five personality traits, and baseline psychological distress levels) on reactions to participation in sensitive topics research. Participants were 504 undergraduates who completed an extensive battery of either trauma/sex questionnaires or cognitive tests and rated their positive and negative emotional reactions and the perceived benefits and mental costs of participating. They also compared research participation to normal life stressors. Our findings indicated that individual difference and demographic risk factors do not increase participant distress after participating in sex/trauma research over and above that experienced after participating in traditionally minimal-risk cognitive tasks. Participants generally found research participation less distressing than normal life stressors and even enjoyable.