A Cox‐Aalen Model for Interval‐censored Data

The Cox‐Aalen model, obtained by replacing the baseline hazard function in the well‐known Cox model with a covariate‐dependent Aalen model, allows for both fixed and dynamic covariate effects. In this paper, we examine maximum likelihood estimation for a Cox‐Aalen model based on interval‐censored failure times with fixed covariates. The resulting estimator globally converges to the truth slower than the parametric rate, but its finite‐dimensional component is asymptotically efficient. Numerical studies show that estimation via a constrained Newton method performs well in terms of both finite sample properties and processing time for moderate‐to‐large samples with few covariates. We conclude with an application of the proposed methods to assess risk factors for disease progression in psoriatic arthritis.     

Measuring performance of two-stage network structures by DEA: A review and future perspective

Data envelopment analysis (DEA) is a method for measuring the efficiency of peer decision making units (DMUs). An important area of development in recent years has been devoted to applications wherein DMUs represent two-stage or network processes. One particular subset of such processes is those in which all the outputs from the first stage are the only inputs to the second stage. The current paper reviews these models and establishes relations among various approaches. We show that all the existing approaches can be categorized as using either Stackelberg (leader-follower), or cooperative game concepts. Future perspectives and challenges are discussed.     

Windows to the Soul? Deliberate Eye Contact as a Cue to Deceit

Although people overwhelmingly believe that liars avoid eye contact, meta-analyses of deception literature have shown a non-significant relationship between gaze and deception. In the present experiment we measured eye movements in an innovative way. We coded the extent to which interviewees deliberately made eye contact with the interviewer. Liars take their credibility less for granted than truth tellers. They therefore may have a greater desire to be convincing and hence more inclined to monitor the interviewer to determine whether they seem to be being believed. We therefore hypothesized that liars would give more appearance of deliberately making eye contact than truth tellers (a relationship which opposes the stereotypical belief that liars look away). A total of 338 passengers at an international airport told the truth or lied about their forthcoming trip. As well as the deliberate eye contact variable, we coded the amount of time the interviewees looked away from the interviewer (e.g., gaze aversion), which is typically examined in deception research. Liars displayed more deliberate eye contact than truth tellers, whereas the amount of gaze aversion did not differ between truth tellers and liars.     

Towards a sociology of transgendered bodies

The articulation of a generic social process of 'body femaling' presented in Ekins (1993) and elaborated in Ekins (1997) is further developed in this article to provide a conceptual framework for a sociology of trans-gendered bodies. Transgendering refers both to the idea of moving across (transferring) from one pre-existing gender category to another (either temporarily or permanently), and to the idea of transcending or living 'beyond gender' altogether. Following Plummer's (1995) work on sexual stories, we distinguish a number of contemporary transgendering body stories which we consider in terms of four major modes or styles of body transgendering: those we identify as 'migrating', 'oscillating', 'erasing' and 'transcending'. We give illustrative examples of each mode with reference to the binary male/female divide, the interrelations between sex, sexuality and gender, and the interrelations between the four main sub-processes of transgendering, which we identify as 'substituting', 'concealing', 'implying' and 'redefining'.     

MENTAL ILLNESS AND THE DEMAND FOR ALCOHOL, COCAINE, AND CIGARETTES

This article estimates the effect of mental illness on demand for addictive substances, allowing for structural endogeneity and simultaneity between mental illness and addictive consumption. Results show that individuals with a history of mental illness are 26% more likely to consume alcohol, 66% more likely to consume cocaine, and 89% more likely to consume cigarettes. This high-participation group is also price-responsive, although their price elasticities differ somewhat from those without mental illness. The results provide added justification for higher taxes and supply reduction activities. Furthermore, subsidizing the treatment of mental illness can reduce addictive consumption.(JEL I1 )     

A projection pursuit index for large <Emphasis Type="Italic">p</Emphasis> small <Emphasis Type="Italic">n</Emphasis> data

In high-dimensional data, one often seeks a few interesting low-dimensional projections which reveal important aspects of the data. Projection pursuit for classification finds projections that reveal differences between classes. Even though projection pursuit is used to bypass the curse of dimensionality, most indexes will not work well when there are a small number of observations relative to the number of variables, known as a large p (dimension) small n (sample size) problem. This paper discusses the relationship between the sample size and dimensionality on classification and proposes a new projection pursuit index that overcomes the problem of small sample size for exploratory classification.     

A bayesian analysis of the mixed linear model

The mixed model is defined. The exact posterior distribution for the fixed effect vector is obtained. The exact posterior distribution for the error variance is obtained. The exact posterior mean and variance of a Bayesian estimator for the variances of random effects is also derived. All computations are non-iterative and avoid numerical integrations.     

Attachment and depression differentially influence nicotine dependence among male and female undergraduates: a preliminary study

The authors surveyed a convenience sample of 208 undergraduate students who reported that they smoked cigarettes. The primary hypothesis they tested was whether gender predicted nicotine dependence. They further tested whether depression and attachment would mediate or moderate this relationship. Hierarchical regression analyses with social desirability and smoking stage of change entered as covariates indicated that women exhibited greater nicotine dependence than men did (p < .01). Lower attachment scores fully mediated this relationship, whereas elevated depression scores moderated the relationship. These findings suggest that depression and the inability to bond with peers may promote nicotine dependence among young female students.