Consistency of minimizing a penalized density power divergence estimator for mixing distribution

In this paper, we study the MDPDE (minimizing a density power divergence estimator), proposed by Basu et al. (Biometrika 85:549–559, 1998), for mixing distributions whose component densities are members of some known parametric family. As with the ordinary MDPDE, we also consider a penalized version of the estimator, and show that they are consistent in the sense of weak convergence. A simulation result is provided to illustrate the robustness. Finally, we apply the penalized method to analyzing the red blood cell SLC data presented in Roeder (J Am Stat Assoc 89:487–495, 1994). This research was supported (in part) by KOSEF through Statistical Research Center for Complex Systems at Seoul National University.     

A note on the equality of the OLSE and the BLUE of the parametric function in the general Gauss–Markov model

In this note we consider the equality of the ordinary least squares estimator (OLSE) and the best linear unbiased estimator (BLUE) of the estimable parametric function in the general Gauss–Markov model. Especially we consider the structures of the covariance matrix V for which the OLSE equals the BLUE. Our results are based on the properties of a particular reparametrized version of the original Gauss–Markov model.      

Deconstructing Immigrant Illegality: A Mixed-Methods Investigation of Stress and Health Among Undocumented College Students

Research has established that being undocumented is a risk factor for mental and physical health conditions. Much of this work emphasizes undocumented immigrants’ chronic stress, yet key questions about pathways to health remain. The mere state of being undocumented is viewed as a general stressor, without considering actual levels of stress or identifying dimensions of documentation status that contribute to overall stress levels. Drawing on surveys and interviews with undocumented students at the University of California, we uncover the everyday manifestations of four dimensions of immigrant “illegality”: academic concerns, future concerns, financial concerns, and deportation concerns, and their association with reported stress levels and self-rated health. Survey data establish undocumented students’ high levels of stress and poorer health, in comparison to previous research on other national samples. In a structural equation model, we found academic and future concerns to be significantly associated with higher stress, which was in turn, associated with poorer self-rated health. Financial concerns were not associated with higher perceived stress but were directly associated with poorer self-rated health. Notably, deportation concerns did not have any significant independent associations with stress or health. We use our qualitative data to identify specific stressors embedded within these four dimensions. Our findings inform understandings of the health risks arising from documentation status.     

Understanding and Using Mediators and Moderators

Mediation and moderation are two theories for refining and understanding a causal relationship. Empirical investigation of mediators and moderators requires an integrated research design rather than the data analyses driven approach often seen in the literature. This paper described the conceptual foundation, research design, data analysis, as well as inferences involved in a mediation and/or moderation investigation in both experimental and non-experimental (i.e., correlational) contexts. The essential distinctions between the investigation of mediators and moderators were summarized and juxtaposed in an example of a causal relationship between test difficulty and test anxiety. In addition, the more elaborate models, moderated mediation and mediated moderation, the use of structural equation models, and the problems with model misspecification were discussed conceptually.

Is the Study of Happiness a Worthy Scientific Pursuit?

This paper critiques the view that the study of happiness is not a worthy scientific pursuit. The happiness set point and hedonic treadmill theories denote the complexity of increasing happiness levels due to genetic limitations and adaptation, however, there is mounting evidence to suggest that with the use of appropriate measures and specific interventions aimed at fostering strengths and virtues, happiness can be increased. Furthermore, the benefits of investigating methods for increasing happiness include improvements in physical, psychological and social health and well-being. It is concluded that approaching human needs from a top down or holistic standpoint where individuals can use their strengths to overcome life’s challenges, is beneficial to health and well-being. Hence, the study of happiness is a worthy scientific pursuit.     

Education,Happiness and Wellbeing

Answers to the questions ‘Does education influence happiness and if so, how and how much?’ depend on how one defines and operationalizes ‘education’, ‘influences’ and ‘happiness’. A great variety of research scenarios may be constructed from our three essential variables. What public policies one ought to adopt and implement regarding the influence of education on happiness depends minimally on which of the great variety of research scenarios one adopts and maximally on lots of other things as well. My personal preference is for a robust definition of the three terms. Because human beings are complex organisms, an adequate construction of the idea of human wellbeing must also be complex. Therefore, any discipline-driven, reductionist definition that pyschologizes, medicalizes, economizes, geneticizes, socializes or politicizes the idea should be avoided.     

India’s Social Development in a Decade of Reforms: 1990–91/1999–2000

The economic reforms initiated in India in 1991 have brought about visible upliftment of economic conditions of the country. This paper examines if the economic process is associated with an enhancement of India’s social development in equal measure in the reform decade of nineties. Ray (1989) considered thirteen social indicators of India and constructed the country’s social development index (SDI) as a certain weighted average of the selected indicators, for the years between 1950–51 and 1975–76. The present work broadly follows Ray (1989) in tracking the social development in the decade of economic reforms from 1990–91 to 1999–2000. The movement of SDI in nineties has been compared with the movements of India’s per capita income and plan expenditure on the social sector. The results show that though there has been growth in the social sector, it is not by far quite encouraging and perhaps more needs to be done in the social sector. The views expressed in the article are those of the author and not of the institution he serves.     

Socio-demographic Differences in Self-reported Psychological Distress Among 25- to 64-Year-Old Finns

Background Mental health problems are a major public health issue worldwide. The aim of this study was to assess the relative importance of socio-demographic characteristics associated with different domains of psychological distress in Finland. Methods Data source was a nationwide survey “Health Behaviour and Health among the Finnish Adult Population” (AVTK), from years 2002 to 2003 (N = 5425; response rate 66%). Psychological distress was measured by self-reported questions of general mental health (MHI-5), depression, insomnia and stress. Socio-demographic factors included education, employment status, partnership and children living in the household. Main analyses were conducted by multivariate logistic regression. Results Education, employment and partnership were associated with most of the psychological distress outcomes. Respondents with a lower educational level had poor mental health in both genders but less insomnia and stress in men. Those with an intermediate education had the least stress in women. The unemployed and retired were at a higher risk for poor mental health and depression. Moreover, employment status was associated with insomnia and stress in men. Respondents not having a partner showed a higher risk of psychological distress according to all measures. Not having children living in the household was associated with insomnia in women and with less stress in men. Conclusions Socio-demographic factors, such as having a partner and employment status, are associated with several measures of psychological distress indicating the importance of social and economic factors to psychological well-being. The association of education and of having children living at home varies by the domain of psychological distress measure.     

The Best and Worst Times of Life: Narratives and Assessments of Subjective Well-Being by Anamnestic Comparative Self Assessment (ACSA) in the Eastern Cape,South Africa

The Anamnestic Comparative Self Assessment (ACSA) measure of subjective well-being (SWB) aims to reduce the problems of cultural bias and relativity to external standards by allowing people to define the endpoints or ‘anchors’ of the measurement scale. In medical terminology anamnestic denotes ‘based on memory’. The ACSA uses subjects’ memories of the best and worst periods in their lives to define the anchors of the scale. They then assess their current quality of life relative to these personal anchors. The South African pilot study tested the match between self-assessment of SWB with ACSA and the conventional single-item measures of life satisfaction and happiness used in the South African Quality of Life Trends Study and analysed the narratives of the best and worst times of life. The quota sample of 46 consisted of 26 residents of Makana district in the Eastern Cape Province, South Africa, and 20 patients undergoing treatment in the local TB hospital. Mean SWB ratings with all three measures of life satisfaction, happiness and ACSA were between 5 and 6 on a 0–10-point scale. Ratings on all three scales were positively correlated. However, on ACSA the TB patients rated their current SWB 1.84 points lower than the community respondents, suggesting a greater sensitivity of this measure. It was observed that the starting points of the life stories produced by respondents to define the anchor periods for ACSA were related to their current assessment of SWB. A typology was developed that combined the starting point of the life stories with current SWB. The majority of community respondents matched the ‘Achiever’ type who scored positively on ACSA (i.e., above the mid-point of the scale) and whose life stories started with the worst period of their lives and proceeded to the best period. The TB patients were the only respondents to represent the ‘Survivor’ type whose morale had recovered after misfortune in life. ‘Survivors’ started their narratives with the best period in their lives, then moved to the worst (often health-related) one, and gave positive ACSA ratings. Based on the qualitative analysis of narratives, it is concluded that ACSA is a sensitive measurement instrument and therefore particularly useful for monitoring the effects of treatments and social interventions in longitudinal studies. However, further research is required to verify its cross-cultural validity.

Are Father’s or Mother’s Socioeconomic Characteristics More Important Influences on Student Performance? Recent International Evidence

Since the early 1970s the importance of mothers’ socioeconomic characteristics on their children’s educational and occupational attainment has been acknowledged. However, it is not clear if fathers’ characteristics have a stronger influence because men usually have stronger attachments to the labour market, or alternatively mothers’ characteristics are more important because of their greater role in children’s socialization. This study addresses this question by comparing the influence of father’s and mother’s education and occupation on student performance in literacy and numeracy using data from 30 countries. The impact of mother’s education is usually greater or comparable to that of father’s education. In contrast, substantially stronger effects for mother’s occupational status compared to father’s were rare. In most countries the impact of mother’s socioeconomic characteristics (education plus occupation) on student performance is comparable to that for father’s. Of the four indicators of socioeconomic background, father’s occupational status and mother’s educational attainment tend to have stronger effects, although many countries do not conform to this pattern. There are indications that the relative importance of mother’s characteristics have increased over time.