Finite mixture modeling of censored regression models

A finite mixture of Tobit models is suggested for estimation of regression models with a censored response variable. A mixture of models is not primarily adapted due to a true component structure in the population; the flexibility of the mixture is suggested as a way of avoiding non-robust parametrically specified models. The new estimator has several interesting features. One is its potential to yield valid estimates in cases with a high degree of censoring. The estimator is in a Monte Carlo simulation compared with earlier suggestions of estimators based on semi-parametric censored regression models. Simulation results are partly in favor of the proposed estimator and indicate potentials for further improvements.     

Estimation of causal effects in observational studies with interference between units

Causal effects are usually estimated under the assumption of no interference between individuals. This assumption means that the potential outcomes for one individual are unaffected by the treatments received by other individuals. In many situations, this is not reasonable to assume. Moreover, not taking interference into account could result in misleading conclusions about the effect of a treatment. For two-stage observational studies, where treatment assigment is randomized in the first stage but not in the second stage, we propose IPW estimators of direct and indirect causal effects as defined by Hudgens and Halloran (J Am Stat Assoc 103(482):832–842, 2008) for two-stage randomized studies. We illustrate the use of these estimators in an evaluation study of an implementation of Triple P (a parenting support program) within preschools in Uppsala, Sweden.     

The Changing Conception of Pension Rights in Canada, Mexico and the United States

Relying on four conceptualizations of the welfare state (universalism, redistribution, state capacity, and intergenerational equity), this article presents an overview of recent pension reforms in Canada, Mexico and the United States. Each country has introduced important reforms in the past 25 years and is currently engaged in debates to make other adjustments. The state is reducing its financial and programmatic commitment towards current and future retirees and is promulgating reforms tightening the link between contributions and benefits. In Canada, the government raised contribution rates substantially to maintain the same level of benefits while it sought to alter its universal flat-rate benefit. In the USA, changes to Social Security have resulted in a higher retirement age and lower replacement rates. In the case of Mexico, the most important public schemes have actually been privatized.     

Vacancy Referrals,Job Search,and the Duration of Unemployment: A Randomized Experiment

One goal of the Public Employment Service is to facilitate matching between unemployed job‐seekers and job vacancies; another goal is to monitor job search so as to bring search efforts among the unemployed in line with search requirements. The referral of job‐seekers to vacancies is one instrument used for these purposes. We report results from a randomized Swedish experiment where the outcome of referrals is examined. To what extent do unemployed individuals actually apply for the jobs they are referred to? Does information to job‐seekers about increased monitoring affect the probability of applying and the probability of leaving unemployment? The experiment indicates that a relatively large fraction (one‐third) of the referrals do not result in job applications. Information about intensified monitoring causes an increase in the probability of job application, especially among young people. However, we find no significant impact on the duration of unemployment.     

Nietzsche’s Sociology1

The aim of this article is to present that part of Friedrich Nietzsche’s work that is of special interest to sociologists. To do this, I discuss the relationship between Nietzsche’s work and the sociology both of today and of his own time. The most important idea is that he saw reality as a social construction. The idea of social construction is related to the beliefs and values, power and interests of the actors. Nietzsche’s discussions of power and of the individual vs. the collective are also analyzed.     

Significant Conversations or Reduced Relational Capacity? Exploring Couple and Family Therapists' Expectations for Including a Client Feedback Procedure

Little information exists on the specific reflective processes that precede therapists' choice of including or not including a structured feedback procedure in their established practice. In the present study, we aim to describe and explore experienced couple and family therapists' expectations for how the comprehensive therapy feedback procedure Systemic Therapy Inventory of Change might influence their practices. Through a thematic analysis of six focus group interviews, two main themes were elicited. The first main theme involved values embedded in current practice, with the following subthemes: (1) balance between the therapist's expert knowledge and the client's experience‐based knowledge; and (2) making time to build alliances. The second main theme concerned the presumed influence on current practice, with the following subthemes: (1) ‘Systemic Therapy Inventory of Change will disturb the therapist's capacity to stay present’; (2) ‘Systemic Therapy Inventory of Change will shape conversations’; and (3) ‘Systemic Therapy Inventory of Change will contribute to increased qualitative depth’. We discuss these results in relation to the notion of Systemic Therapy Invention of Change as a ‘third party in the room’. We also discuss the results in relation to implications for collaborative practices, and for client and therapist autonomy.     

Trade shows and the creation of market and industry

This study addresses the question of the constitution of markets in advanced societies. Specifically, the article studies the role of the traveling trade show in creating the real time computing market, which is part of the US electronics sector, during the mid‐1990's. Real time computing products assist the transfer, storage and processing of digital signals in real time and support many of the internet applications we use today. By applying ethnographic methods, we explore the general question of how economic actors cope with uncertainty in the phase of market‐making and at the cutting edge of technology. The paper makes two contributions to the existing literature. First, it shows that the attempt to organize a trade show in real time computing was triggered by the uncertainty experienced by sellers regarding the identity of prospective buyers and about the exact use to which they would put the emergent technology which is offered for sale. Secondly, we trace the history of an emergent market. We claim that trade shows for innovative products are important venues at which markets coalesce. The identification and ordering of market actors, the institutionalization of a distinct business culture and the social networks developed among market actors and across the subsidiary markets provided the basic social infrastructure for what later became known as the real time computing industry.     

Occupational Identity in Administrative Service Work: The Aspect of Carefulness

This article explores ‘carefulness’ as a salient aspect of occupational identity in two administrative service occupations. Drawing on empirical data obtained through interviews with medical secretaries and post‐office cashiers, and on a theoretical perspective sensitive to different bases of identification and classification, the meanings and ambiguities of carefulness are discussed in a wider context of gender, modernity and office work. The empirical material indicates that the theme of carefulness is closely connected to issues of competence and power. It is the author's argument that a closer focus on competence‐related themes and concepts central to working individuals themselves, combined with an occupational identity approach that takes modernity as well as gender into consideration, will contribute to a better understanding of the contested realities of administrative service work.     

Effects of psychosocial interventions on behavioural problems in youth: A close look at Cochrane and Campbell reviews

Research indicates that a number of psychosocial interventions are effective for reducing behavioural problems in youth. These interventions are now often included on best practice lists aiming to facilitate informed treatment choices among practitioners. However, analyses in neighbouring research areas have highlighted serious shortcomings in how primary studies are analysed and how studies are synthesised in research reviews. This study took a closer look at the evidence of efficacy for psychosocial interventions that aim to reduce behavioural problems in youth, as shown in systematic research reviews by the Cochrane and the Campbell Collaborations (n = 8). The findings suggest a bias towards overemphasising the efficacy of the interventions in several reviews, an over‐confidence in the validity of the findings in some reviews and, overall, a somewhat uncertain evidence base for the efficacy of the interventions. Systematic reviews are crucial for summarising research but more attention to methodological issues may be needed in this area.     

Testing for normally in censored regressions

This paper derives a Lagrange Multiplier test for normality in censored regressions. The test is derived against the generalized log-gamma distribution, in which normal is a special case. The resulting test statistic coincides to some extent with previously suggested score and conditional moment tests. Estimation of the variance is performed by using the matrix of second order derivatives in order to get an easy to use test statistic. Small sample performance of the test is studied and compared to other tests by Monte Carlo experiments.