THE POWER OF STUDENT'S t TEST: CAN A NON-SIMILAR TEST DO BETTER?

Lehmann & Stein (1948) proved the existence of non-similar tests which can be more powerful than best similar tests. They used Student's problem of testing for a non-zero mean given a random sample from the normal distribution with unknown variance as an example. This raises the question: should we use a non-similar test instead of Student's t test? Questions like this can be answered by comparing the power of the test with the power envelope. This paper discusses the difficulties involved in computing power envelopes. It reports an empirical comparison of the power of the t test and the power envelope and finds that the two are almost identical especially for sample sizes greater than 20. These findings suggest that, as well as being uniformly most powerful (UMP) within the class of similar tests, Student's t test is approximately UMP within the class of all tests. For practical purposes it might also be regarded as UMP when moderate or large sample sizes are involved.     

Postdivorce Father‐Adolescent Closeness

Research indicates that closeness of the father‐child bond following parental divorce is associated with better outcomes for children and adolescents. Unlike other investigations, this study takes a long‐term developmental approach to understanding stability and change in postdivorce father‐adolescent relationship closeness. Drawing on Add Health data (n = 483), we examine factors that explain (a) why some high‐quality father‐adolescent relationships remain the same after divorce whereas others decline, and (b) why some low‐quality relationships are stable following divorce whereas others improve. High mother‐offspring relationship quality and offspring feelings of well‐being prevented close father‐offspring relationships from deteriorating. Offspring’s childbearing and cohabitation following parental divorce increase closeness in father‐offspring relationships that were not close prior to divorce. Although a majority of offspring experienced a decline in closeness following divorce, results from this study show that some very close father‐offspring relationships are maintained and some poor relationships become closer.     

Corporate political power and US foreign policy, 1981–2002: the role of the policy-planning network

Theory and Society - Recent empirical work has offered strong support for ‘biased pluralism’ and ‘economic elite’ accounts of political power in the United States, according...     

Disability and climate change: A critical realist model of climate justice

Existing literature on climate change as an issue of environmental justice documents the heightened vulnerability of people with disabilities to the effects of climate change. Additionally, there are numerous studies showing that access to information is a prerequisite for perceiving risk and taking action. Building on this work, our review seeks to understand how physical disability relates to perceptions of climate-related risk and adaptations to climate-related events. We introduce a critical realist model of climate justice to understand the relationships between the environmental features that disable, risk perception and information seeking, and adaptive capacity and resilience to climate change. In understanding the vulnerability and adaptive capacity of people with disabilities to climate change, this review synthesizes research on one of the U.S.’s largest minority communities with the goals of better understanding how vulnerable populations cope with climate change and integrating them into climate action and policy.     

Subjective Health-Related Quality of Life in Homeless and Vulnerably Housed Individuals and Its Relationship with Self-Reported Physical and Mental Health Status

Although the association between homelessness and objective indicators of poor health is well-established, little research has focused on the subjective health-related quality of life of homeless and vulnerably housed (HVH) individuals. This study examined the subjective health-related quality of life of HVH individuals, using the Multiple Discrepancies Theory (MDT) Scale for Health of the Quality of Life for Homeless and Hard-to-House Individuals (QoLHHI) Inventory, and its association with self-reported functional health status, as measured by the SF-12, and self-reported physical and mental health conditions in a sample of 100 HVH individuals recruited in Vancouver, Toronto and Ottawa. Our findings indicate that physical and mental health conditions are highly prevalent among HVH individuals and that the SF-12 Physical and Mental Component Summary scores are substantially lower compared to US population norms. The MDT Health items were not statistically significantly associated with physical or mental health conditions and only showed correlations of small to moderate magnitude with the SF-12 Component Summary Scales. These findings suggest that the QoLHHI MDT Scale for Health can provide information about HVH individuals’ subjective health experiences that is different from, and can serve as a valuable complement to, health status information for use in research and evaluation studies, as well as for policy purposes to make informed decisions based on subjective health-related quality of life data from HVH individuals.     

How Does Relative Income and Variations in Short-Run Wellbeing Affect Wellbeing in the Long Run? Empirical Evidence From China’s Korean Minority

Cognitively appraised life satisfaction is relatively stable over time and can be considered as reflecting subjective wellbeing in the long run. Affect is transitory and can be considered as reflecting subjective wellbeing in the short run. Using the Personal Wellbeing Index to measure cognitively appraised life satisfaction and the Positive and Negative Affect Schedule to measure positive and negative affect we examine how income relative to one’s comparator group and variations in short run wellbeing impact upon wellbeing in the long run. We do so for China’s Korean ethnic minority. We find that affective state has an effect on wellbeing in the long run and that a negative shock to affectivity is more persistent than a positive shock. We also find that relative income, rather than absolute income, matters for wellbeing in the long run and that the results are consistent with a status effect.     

When Are Net Effects Gross Products? Communication

The rush to judgment about the social effects of the new communications media has branded them as positive and negative in equal measure. Alienation from "real world" relationships coupled with a lack of social regulation within the medium is balanced by liberation from the influences, inequalities, and identities to which people are subjected in face-to-face interaction. We argue that such general conclusions may in fact be turned upside down and propose that these media may actually strengthen social bonds but also reinforce power inequalities. Reviewing evidence of our research with university students, employing the social identity model of deindividuation effects, we show how these technologies can often be more "social," and socially regulated, than face-to-face interaction.     

What Determines the Extent to which Employers will Comply with their Social Security Obligations? Evidence from Chinese Firm‐level Data

This article aims to extend understanding of employer responses to social protection regulations enacted by government to ensure the well‐being and security of employees. By utilizing firm‐specific data collected from Shanghai we explore the relationship between firm characteristics, employer behaviour, and the effectiveness of compliance mechanisms that have been adopted to contain contribution evasion by employers. We offer empirical evidence about the impact of the size of the firm, ownership structure, and incidence of risk on employer evasion behaviour in social protection payments. These results should enable enforcement agencies to improve compliance levels and also contribute to building theory as regards the significance of social policies to employers and the impact of social protection on human resource policy.