An improved alternative estimation procedure for current population mean in presence of positively and negatively correlated auxiliary variables in two-occasion rotation patterns

Abstract

The present study confirms the influential role of a positively and a negatively correlated auxiliary variables in enhancing the precision of estimates of current population mean in two occasion rotation (successive) sampling. Exponential-type estimators of current population mean have been proposed for three different situations: (i) the information on a positively correlated auxiliary variable is readily available on both occasions (ii) the information on a negatively correlated auxiliary variable is readily available on both occasions and (iii) the information on both positively and negatively correlated auxiliary variables are readily available on both the occasions. The characteristics of the proposed estimators have been explored and their efficacious performances are compared with the natural and recent contemporary estimators. Optimum replacement strategies of the proposed estimation procedures have been formulated. Simulation and empirical studies are carried out to justify the proposition of the proposed estimators and appropriate recommendations have been put forward to the survey practitioners.     

Exact Likelihood Inference for k Exponential Populations Under Joint Type-II Censoring

In this paper, when a jointly Type-II censored sample arising from k independent exponential populations is available, the conditional MLEs of the k exponential mean parameters are derived. The moment generating functions and the exact densities of these MLEs are obtained using which exact confidence intervals are developed for the parameters. Moreover, approximate confidence intervals based on the asymptotic normality of the MLEs and credible confidence regions from a Bayesian viewpoint are also discussed. An empirical comparison of the exact, approximate, bootstrap, and Bayesian intervals is also made in terms of coverage probabilities. Finally, an example is presented in order to illustrate all the methods of inference developed here.     

An Empirical Analysis of Some Nonparametric Goodness-of-Fit Tests for Censored Data

In this article, we consider some nonparametric goodness-of-fit tests for right censored samples, viz., the modified Kolmogorov, Cramer–von Mises–Smirnov, Anderson–Darling, and Nikulin–Rao–Robson χ² tests. We also consider an approach based on a transformation of the original censored sample to a complete one and the subsequent application of classical goodness-of-fit tests to the pseudo-complete sample. We then compare these tests in terms of power in the case of Type II censored data along with the power of the Neyman–Pearson test, and draw some conclusions. Finally, we present an illustrative example.     

Grandmothers' influence on mother and child health

This study is based on interviews with grandmothers during July-September 1992-93 in Sudan. The study shows that grandmothers play a significant role in health education and child care within families in the Sudan. Grandmothers, who are not aware of the changes in knowledge, also promote harmful traditions. The authors recommend that health education be directed to elderly women and grandmothers in order to change beliefs and practices that continue to be harmful to children and mothers. Grandmothers were found to give sound advice on child birth, such as movement during labor, breast feeding immediately after birth, and birth intervals of 2-4 years. Grandmothers also gave sound advice on good nutritional practices during pregnancy and use of fermented cereals as weaning foods. Grandmothers recommended use of fenugreek for lactating mothers and use of mint and haharaib for stomach upsets, remedies that are beneficial. Babul is useful after an episiotomy for its antibacterial effects. Harmful advice includes recircumcision after delivery, short birth intervals, and avoidance of contraception. Female genital mutilation (FGM) is a major practice that exposes girls and mothers to a greater risk of mortality during childbirth and pregnancy. The sample of grandmothers agreed on the importance of sex education for a girl before marriage. Unfortunately, 57% of grandmothers recommended 14 years as a suitable age for marriage. Grandmothers generally believed wrongly that riding bicycles, drinking coffee, and wearing trousers by girls would increase their sexual desires. Grandmothers explained menstruation to granddaughters and offered home-made remedies for cramps. 45% believed that there were no disadvantages to FGM and recommended FGM at ages 2-5 years. Most viewed fevers as a danger that required a doctor's care. Advice varied among grandmothers according to socioeconomic class.     

Emigration dynamics from and within South Asia

This review of current knowledge about emigration dynamics from and within South Asia (Bangladesh, India, Pakistan, and Sri Lanka) opens with a brief history of the three phases of emigration from the area since the 1830s (plantation labor; postindependence to the UK, US, Canada, and Australia; and labor migration to the oil-exporting countries). The influence of the creation of Pakistan and Bangladesh is also covered as are British colonial and commonwealth policies. It is noted that migration data are incomplete and that India exhibits an ambivalence about collecting such information. The discussion then turns to emigration since 1970 and considers permanent migration from South Asia to the traditional receivers; South Asian asylum seekers in Europe; South Asian refugees, illegal migrants, migrant workers (flows and destinations), the stock of contract migrant workers (and their characteristics); returnee migrant workers; and skill levels. Analysis is provided of macro level determinants of emigrations such as gross national product (level and growth), the general demographic and social situation, labor force growth and structure, poverty and inequality, and internal and international migration. Environmental factors causing displacement in Southern Asia include floods, cyclones, river bank erosion, drought, and desertification. Global warming could displace millions of people in the region, and development projects have contributed to displacement. The remainder of the report covers political and ethnic factors, micro-factors influencing migration decision-making, the policies of sending and receiving countries, the consequences of emigration, and the potential for migration in the future.     

Progress and cumulation in the human sciences after the fall

What do we mean by progress and cumulation in the social and human sciences? Recent thinking in the philosophy and history of science has led to an abandonment of some versions of logical positivism and of verificationism that had a strong deductive and theory testing orientation. What is to replace them is less clear. This paper argues that progress and cumulation can be seen as a process of evaluation and retention within an epistemic community. Scholarly disciplines differ in their social structure and in their epistemic and normative commitments. Since sociology is a fragmented discipline, progress and cumulation differ within its multiple subdisciplines, which to varying extents represent epistemic communities. Brief sketches of progress (advance) and cumulation in several subdisciplines are offered.     

Does intergenerational mobility shape psychological distress? Sorokin revisited

Drawing from Sorokin's hypothesis that socially mobile individuals are at greater risk of experiencing psychological distress than their non-mobile counterparts, we investigate whether intergenerational occupational mobility influences psychological distress, as measured by the Center for Epidemiologic Studies Depression (CES-D) scale. Using data for men from the Wisconsin Longitudinal Study (WLS) and Sobel's Diagonal Mobility Models, we find little evidence for Sorokin's hypothesis; mobile individuals are no more likely to be psychologically distressed than their non-mobile counterparts. In fact, one group of mobile men - those who left their farming origins - are actually less distressed than the sons who remain as farmers and non-mobile men in higher-ranked social classes. We speculate that this reflects the fact that farming became very arduous during the late 20th century and these mobile sons of farmers appreciate their improved life chances. Our findings suggest that the association between mobility and psychological distress varies across specific class backgrounds and is contingent upon the broader social and economic context.     

Implicit prejudicial biases in student learning: the effects of sexual orientation

In an investigation of students' potential biases toward gay and lesbian instructors, 93 female and 59 male undergraduates viewed a lecture, rated the instructor and perceived learning, and completed a lecture-retention test. Lectures were given by a man or woman, identified as straight or gay or lesbian. Sexual orientation did not affect the instructor evaluation or perceived learning ratings for any of the groups. Although sexual orientation did not affect the lecture-retention scores for the female students, learning by the male students was significantly lower with the gay male instructor than with the straight male instructor (p = .03), suggesting an implicit bias.     

Psychosocial predictors of self-esteem in a multiethnic sample of women over 50 at risk for HIV

Self-esteem is linked to high-risk behaviors in other populations but has not been examined in women aged 50 and older. This study explored how self-esteem is related to variables that can influence high-risk sexual behaviors in women over 50. A multiethnic community-based sample of 572 women aged 50 and older completed an anonymous questionnaire on sexual behaviors, sociodemographic characteristics, and psychosocial measures relevant to midlife and older women. Regression analysis showed sensation-seeking, HIV stigma, sexual assertiveness, and self-silencing predicted self-esteem in women over 50 (F = 43.632, p < .001). Factors such as relational context, interpersonal power, and silencing can affect self-esteem and may be contributing to HIV risk in this group.     

The Structure of Pregnancy Intervals by Planning Status

Measures of pregnancy intervals are reported for data from the 1975 National Fertility Study in the United States. The structure of such intervals is aggregated into its components by planning status. A measurement model is devised to infer from a survival function some dimensions of the initial distribution of respondents by propensity to experience the event in question. It is adaptable to the study of reproductive intention as well as fecundability and contraceptive effectiveness. The model is applied to the study of the dependence of such behaviour in a given interval on the planning status of the previous pregnancy. Planning status is sequentially well-ordered. Those previously successful with contraceptive use are less likely to fail than those who had previously failed; those who had previously used contraception, whether successful or not, are less likely to fail than those who had not previously used. The credibility of the findings is prejudiced less by the form of model than by the reliability of the basic data.