A note on estimating regression coefficients with missing data

In this note, we consider the problem of estimating regression coefficients when there are missing observations of some explanatory variables. Following Dagenais (1973), Gourieroux and Monfort (1981), and Conniffe (1983a, 1983b), we assume auxiliary relationships exist among explanatory varibles. Several estimatprs and their interrelationships are discussed. We begin with the model of Gourieroux and

Monfort (1981)     

Assessing Risk‐Based Upper Limits of Melamine Migration from Food Containers

Melamine contamination of food has become a major food safety issue because of incidents of infant disease caused by exposure to this chemical. This study was aimed at establishing a safety limit in Taiwan for the degree of melamine migration from food containers. Health risk assessment was performed for three exposure groups (preschool children, individuals who dine out, and elderly residents of nursing homes). Selected values of tolerable daily intake (TDI) for melamine were used to calculate the reference migration concentration limit (RMCL) or reference specific migration limit (RSML) for melamine food containers. The only existing values of these limits for international standards today are 1.2 mg/L (0.2 mg/dm²) in China and 30 mg/L (5 mg/dm²) in the European Union. The factors used in the calculations included the specific surface area of food containers, daily food consumption rate, body weight, TDI, and the percentile of the population protected at a given migration concentration limit (MCL). The results indicate that children are indeed at higher risk of melamine exposure at toxic levels than are other groups and that the 95th percentile of MCL (specific surface area = 5) for children aged 1–6 years should be the RMCL (0.07 mg/dm²) for protecting the sensitive and general population.     

Tracing the roots of mindfulness: Transcendence in Buddhism and Christianity

The field of social work has embraced mindfulness skills in the training of social workers and as an intervention used in practice. However, there is little discussion regarding the theoretical or religious roots of mindfulness. In addition, social workers often employ mindfulness by practicing within a behaviorist frame. Missing from this behaviorist frame are the historic religious definitions, aims, and values of mindfulness, which lead to a fuller understanding of mindfulness in social work practice. This article traces the religious roots of mindfulness to clarify its goals in both Buddhism and Christianity, with an emphasis on the Mahayana branch of Buddhism and the contemplative and mystical traditions within Christianity. In both religions, mindfulness leads one to an experience of transcendence, assisting the follower to realize that the self belongs in relationship with a divine oneness in Buddha nature, that is believed to be intrinsic to all sentient beings (in Buddhism), or a divine God through the person of Jesus Christ (in Christianity) where the self is retained. Social workers uphold the values of mindfulness and the profession itself when being sensitive to root mindfulness practice within its historical and religious contexts, particularly within Buddhist and Christian faith systems.     

A property of coefficients of variation for ordered bivariate log-normal variables

This paper considers the maximum and minimum of a pair of log-normal variables with equal mean. It shows that either order statistic has a smaller coefficient of variation than the two original log-normal variables provided the latter are of equal variance. When the variances are unequal, as the variance ratio increases, the minimum (maximum), has a smaller coefficient of variation if the correlation coefficient of the log-normal variables is small (small) and the variances are large (small).     

The roles of human capital and social capital in the economic integration of new arrivals from Mainland China to Hong Kong

Although it has been hypothesized in the literature that both human capital and social capital are important for the economic performance of new immigrants, few studies have examined these relationships empirically, especially in understudied populations such as Chinese populations. This study simultaneously examines the roles of human capital and social capital in the economic integration of new arrivals from Mainland China to Hong Kong, using a random sample of immigrants. In the early stage of immigration (less than 6 months after arrival), we find little support for the presumed positive effects of both human capital and social capital on employment status among new arrivals in Hong Kong. Follow-up studies are underway to investigate the dynamic relationship between social capital and economic integration in this group of new arrivals, and whether social capital, especially friendship networks, plays a more important role in the economic integration of new immigrants 1 or 2 years after arrival.     

Home Modifications among Community-Dwelling Older Adults: A Closer Look at Race and Ethnicity

ABSTRACT

This study investigated racial and ethnic differences in home modification use. Data from the 2011 National Health and Aging Trends Study were used (n=6,764). Compared with non-Hispanic Whites, Hispanics were less likely to have a grab bar (odds ratio (OR) = 0.6), bath seat (OR = 0.8), or raised toilet (OR = 0.6). Non-Hispanic Blacks were less likely to have a grab bar (OR = 0.7) or bath seat (OR = 0.7) than non-Hispanic Whites, but more likely to have a raised toilet (OR = 1.3). English proficiency largely explained ethnic differences, while health status partially accounted for racial disparities.     

Getting to Where You Want to Go: Designing Information Systems and Using Your Data Through the Application of Analytics and Informatics

ABSTRACT

This article, based on the closing session from the 2017 NC Serials Conference, describes a systems perspective where data serve as both real-time and summative information and knowledge about how an organization is performing, what services and resources its users are using and interacting with, and areas for which the organization is doing well or needs improvement. The author posits that data are most useful when the context is informed by clear goals that provide a direction to where the organization is and wants to be. Applied examples are discussed for several environments, including an academic department, school of education, regional libraries, and public libraries.     

Chinese State Bureaucracy and Democratization: Contradictions and Strategization

Joining the current debate in the field of China studies, this paper argues that the two extremes of the inevitability and impossibility of democratization are not necessarily the only two trajectories of political development in China and that China can develop a genuine democracy that builds on, and in turn nurtures, responsible citizenship and administratorship, if CPC undertakes strategization to cope with the fundamental contradictions between democratization and political monism and reactionary logic of administration. Two examples of strategizing actions are given to illustrate how democratization may be enhanced.     

On the estimation of variance components in stability analysis

Chow and Shao (1989, 1991) indicated that the presence of batch-to-batch variation has an impact on the determination of drug shelf-life in stability studies. In this paper, we propose two unbiased estmators for batch-to-batch variation. The proposed estimators are compared in terms of their corresponding variances. An example concerning a stability study is discussed to illustrate the use of the proposed estimators.     

Domestic Violence Service Providers’ Needs and Perceptions of Technology: A Qualitative Study

There is growing recognition of the need to better understand the intersections between the work of domestic violence service providers and technology. Professionals who work with clients impacted by domestic violence are increasingly using technologies across different aspects of their work, including communicating with other professionals and seeking information and resources via the Internet. The current study used qualitative data from two sources—individual interviews and two focus groups—to learn about domestic violence service providers’ needs and perceptions related to technology use. The results provide insights about technologies used currently, expected benefits of future technological advances, barriers to using technology, and participants’ self-rated levels of comfort with technology.