A unified approach to multilevel sample selection models

Abstract

We propose a unified approach for multilevel sample selection models using a generalized result on skew distributions arising from selection. If the underlying distributional assumption is normal, then the resulting density for the outcome is the continuous component of the sample selection density and has links with the closed skew-normal distribution (CSN). The CSN distribution provides a framework which simplifies the derivation of the conditional expectation of the observed data. This generalizes the Heckman’s two-step method to a multilevel sample selection model. Finite-sample performance of the maximum likelihood estimator of this model is studied through a Monte Carlo simulation.     

A Semiparametric Bayesian Model for Circular-Linear Regression

Circular data are observations that are represented as points on a unit circle. Times of day and directions of wind are two such examples. In this work, we present a Bayesian approach to regress a circular variable on a linear predictor. The regression coefficients are assumed to have a nonparametric distribution with a Dirichlet process prior. The semiparametric Bayesian approach gives added flexibility to the model and is useful especially when the likelihood surface is ill behaved. Markov chain Monte Carlo techniques are used to fit the proposed model and to generate predictions. The method is illustrated using an environmental data set.     

Puberty in the Last 25 Years: A Retrospective Bibliometric Analysis

Puberty research has been highly productive in the past few decades and is gaining momentum. We conducted an analysis of bibliographic data, including titles, abstracts, keywords, indexing terms, and citation data to assess the sheer numbers, audience and reach, publication types, and impact of puberty‐related publications. Findings suggest that puberty‐related publications are increasing in sheer numbers, and have reach in many fields as befits an interdisciplinary science. Puberty‐related publications typically have higher impact in terms of citations than the journal averages, among the journals that published the most studies on puberty. Limitations of the field and recommendations for researchers to improve the impact and reach of puberty‐related publications (e.g., clear conclusions in abstracts, highlighting the importance of puberty) are discussed.     

Re-examining pregnancy-related anxiety: A replication study

Background

Recognition of pregnancy-related anxiety as a distinct anxiety is supported by evidence differentiating it from general anxiety and depression. Adverse associations with pregnancy-related anxiety further support this distinction. An influential study by Huizink et al. (2004), demonstrated that anxiety and depression contribute little to the variance of pregnancy-related anxiety, yet this study has not been replicated. Further, addressing limitations of the original study will provide further clarity to the findings.

At the intersection of idealized youth and marginalized almost-adulthood: how girls negotiate young motherhood in London,Ontario

This article discusses how young mothers in London, a mid-size city in Canada, utilize a drop-in centre service while attending an alternative programme to acquire secondary school credits. The central arguments made here are informed by key concepts in the field of girlhood studies. With its attention to the interconnections between gender, age, and generation as well as other aspects of social identity, girlhood studies provides crucial insight into the lived experiences of young mothers who straddle the space between girlhood and adulthood. We interpret the experiences of the young mothers who participated in this study in light of shifting meanings and expectations of girls and girlhood in the neoliberal era. Drawing on the concept of the ideal neoliberal girl subject embodied in the ‘can do’ and ‘at risk’ girl, this paper highlights the tensions in accessing a drop-in centre, which functions as both a site of security and surveillance, for a group of young mothers receiving social services. The findings revealed how girls who are mothers struggle to live in the present to assert a legitimate maternal identity even as they are prepared for the future through neoliberal public policies and other disciplinary practices.     

Facilitation and Dialogue as Methods of Reflective Practice in Professional Education

Students may fear sharing their learning in public because classrooms are not traditional places where we teach skills needed for mutual understanding, such as facilitation and dialogue. This is a pedagogical challenge for planning, policy, and design fields because contemporary teaching requires collaboration among participants. We propose that learning to work collaboratively in the classroom has broader relevance for practice because it mirrors the learning that happens in organizations. To address this opportunity, we trained students in facilitation and dialogue. In this article, we discuss the design, implementation, and outcomes of this intervention.     

Two Perspectives on the Language of Special Needs Computing: towards a shared view

This paper reviews and examines the language used in literature that describes the educational and therapeutic use of microcomputers with people who have special needs. In the language of special needs computing two perspectives are identified. One perspective focuses on the microcomputer technology while the other focuses on the microcomputer user. While the language of both perspectives acknowledges the value of microcomputers, each perspective moves towards an acknowledgement that microcomputer use needs to be placed in an environmental context. This move in both language sets reflects an increasing focus on the potential barriers to microcomputer use.