Semiparametric estimation for count data through weighted distributions

This paper is concerned with semiparametric discrete kernel estimators when the unknown count distribution can be considered to have a general weighted Poisson form. The estimator is constructed by multiplying the Poisson estimate with a nonparametric discrete kernel-type estimate of the Poisson weight function. Comparisons are then carried out with the ordinary discrete kernel probability mass function estimators. The Poisson weight function is thus a local multiplicative correction factor, and is considered as the uniform measure to detect departures from the equidispersed Poisson distribution. In this way, the effects of dispersion and zero-proportion with respect to the standard Poisson distribution are also minimized. This method of estimation is also applied to the weighted binomial form for the count distribution having a finite support. The proposed estimators, in addition to being simple, easy-to-implement and effective, also outperform the competing nonparametric and parametric estimators in finite-sample situations. Two examples illustrate this new semiparametric estimation.     

可以容忍的不平等：过渡与差别--柯亨思想的一种政治哲学考量

柯亨认为,马克思主义追求的社会主义理想是消除资本主义的阶级剥削,代之以经济平等和彻底的民主,但是,从历史和现实看,我们都距离马克恩的理想有很大距离。即使作为当前的合理目标是最好的选择,市场社会主义至多仍然是次优的选择。鉴于历史发展的进程要求,即过渡特征,我们必须对结果意义上的各种不平等采取包容政策。但在社会主义机会平等的条件下,收入差异在仅仅反映了不同的收入、闲暇差异时才是可以接受的。社会主义平等并非“机械的平等”或“结果的相同”。     

Toward a teacher solidarity lens: former teachers of color (re)envisioning educational research

Based on a two-year self-study by a group of early-career scholars of color, we explore and purposefully name our role, within the contemporary context of neoliberal reform, as educational researchers of color who are former K-12 teachers. We capture the insights that emerged from our self-study through a close reading of dominant neoliberal educational reform discourses, particularly through an examination of the writings of Michelle Rhee and Wendy Kopp. Along three dimensions of: (1) experience as teachers; (2) solidarity with teachers; and (3) analyses of racism in schooling, we characterize prominent discourses through which educators, researchers, and the public describe teachers and teaching. We name these discursive frames to make explicit the assumptions that are embedded in each and the intentional or inadvertent consequences of each. Finally, we propose a teacher solidarity lens through which we strive to approach our research and work with teachers.     

Saving behaviour and earnings uncertainty: Evidence from the British Household Panel Survey

For the first time, this paper uses a panel data set, the British Household Panel Survey, to analyse saving behaviour in Britain. One objective is to test the precautionary saving hypothesis, according to which households save to self-insure against uncertainty. Our results show that in accordance with this hypothesis, various measures of uncertainty based on earnings variability have a statistically significant effect on households' saving decisions. Moreover, in accordance with the life cycle model, households save more if they expect their financial situation to deteriorate. Received: 15 June 1999/Accepted: 4 January 2001     

Childhood family structure and young adult behaviors

This paper examines a wide variety of forms, and full histories, of family structure to test existing theories of family influences and identify needs for new theories. The focus is on links between childhood family structure and both completed schooling and risk of a nonmarital birth. Using a 27-year span of panel (PSID) data for U.S. children, we find that: (a) change is stressful, (b) timing during childhood is relevant, (c) adults other than parents are important, and (d) two more recently studied family structures (mother-with-grandparent(s) and mother-with-stepfather) do not fit the molds of existing theories. The findings suggest that new theories should consider allocation of resources and reasons people group into family structures. Received: 11 September 1998/Accepted: 27 March 2000     

Does the Role of Student Factors with Adolescent Substance Use Vary by Geography?

This study assesses the association of 12th-grade student factors (e.g., grades, classroom misbehaviors) with substance use (i.e., binge drinking, cigarette smoking, marijuana) across large, medium-sized, and nonmetropolitan areas. Based on a sample of 2,189 students from the 2013 Monitoring the Future data set, logistic regression analyses showed that poor student academic and behavioral factors were associated with higher substance use after controlling for gender, race, and socioeconomic status. Interaction analyses further showed no significant differences in the influence of student factors on substance use across locales. Results suggest that prevention efforts against substance use should target student factors regardless of area of residency.     

Relearning to Live Life Without Substances: A Grounded Theory of the Impact of Group Physical Exercise on Sobriety

Research has found significant benefits in using exercise as an adjunct treatment for substance use. This study used a qualitative grounded theory approach to explore the role of group exercise on maintaining sobriety. Sixteen persons (13 White men and 3 White women, age M = 31.81, SD = 8.23), recruited from a substance use recovery group that meets at a gym in an urban area in the Southeast part of the United States, were individually interviewed. Data were analyzed using Charmaz’s (2006) constructivist grounded theory strategies. Central themes revealed a parallel process between the steps taken to seek sobriety and those taken to maintain sobriety. The driving forces of sobriety success in both was 12 steps and group exercise programming that included elements of mentorship, structure, accountability, and fellowship or community. This study supported the use of physical group exercise as an adjunct treatment option for substance use treatment.     

Investment model predictions of workplace ostracism on K–12 teachers’ commitment to their schools and the profession of teaching

The purpose of this study was to determine how the ostracism of K-12 teachers influences their commitment to their schools and commitment to the teaching profession. The investment model was used to situate ostracism as a predictor of teacher commitment. Participants were 200 full-time K-12 teachers who completed a survey assessing their experiences with ostracism at work and investment model variables (i.e., investments, quality of alternatives, satisfaction, and commitment). Results confirmed investment model predictions with teachers’ investments, quality of alternatives, and satisfaction predicting their commitment to their schools and profession. Results of mediation models also demonstrated that controlling for teachers’ investments and quality of alternatives, ostracism predicted commitment indirectly through its effect on satisfaction. This study revealed that teacher commitment is explained by investment model predictions, but after controlling for those predictions, is further explained by ostracism from teacher colleagues.