Admissible estimation in an one parameter nonregular family of absolutely continuous distributions

Consider the problem of estimating under squared error loss an arbitrarily positive, strictly increasing or decreasing parametric function based on a sample of size n in an one parameter nonregular family of absolutly continuous distributions with both endpoints of the support depending on a single parameter. We first provide sufficient conditions for the admissibility of generalized Bayes estimators with respect to some specific priors and then treat several examples which illustrate the admissibility of best invariant estimators in some location or scale parameter problems.     

A note on some negative dependence notions

A random vector X = (X ₁,…,X _n ) is negatively associated if and only if for every pair of partitions X ₁ = (X _π(1),…,X _π(k)), X ₂ = (X _π(k+1),…,X _π(n)) of X , P( X ₁ ? A, X ₂ ? B) ≤ P( X ₁ ? A)P( X ₂ ? B) whenever A and B are open upper sets and π is any permutation of {1,…,n}. In this paper, we develop some of concepts of negative dependence, which are weaker than negative association but stronger than negative orthant dependence by requiring the above inequality to hold only for some upper sets A and B and applying the arguments in Shaked.     

Tests for detecting overdispersion in poisson models

Collings and Margolin(1985) developed a locally most powerful unbiased test for detecting negative binomial departures from a Poisson model, when the variance is a quadratic function of the mean. Kim and Park(1992) developed a locally most powerful unbiased test, when the variance is a linear function of the mean. It is found that a different mean-variance structure of a negative binomial derives a different locally optimal test statistic.

In this paper Collings and Margolin's and Kim and Park's results are unified and extended by developing a test for overdispersion in Poisson model against Katz family of distributions, Our setup has two extensions: First, Katz family of distributions is employed as an extension of the negative binomial distribution. Second, the mean-variance structure of the mixed Poisson model is given by σ² = μ+cμ^r for arbitrary but fixed r. We derive a local score test for testing H₀ : c = 0. Superiority of a new test is proved by the asymtotic relative efficiency as well as the simulation study.     

Asymptotic test of mixture model and its applications to QTL interval mapping

Quantitative trait loci (QTL) mapping has been a standard means in identifying genetic regions harboring potential genes underlying complex traits. Likelihood ratio test (LRT) has been commonly applied to assess the significance of a genetic locus in a mixture model content. Given the time constraint in commonly used permutation tests to assess the significance of LRT in QTL mapping, we study the behavior of the LRT statistic in mixture model when the proportions of the distributions are unknown. We found that the asymptotic null distribution is stationary Gaussian process after suitable transformation. The result can be applied to one-parameter exponential family mixture model. Under certain condition, such as in a backcross mapping model, the tail probability of the supremum of the process is calculated and the threshold values can be determined by solving the distribution function. Simulation studies were performed to evaluate the asymptotic results.     

The Impact of Age and Health on Vehicle Choices among Elders

We examine older Americans’ choice of vehicle types and the impact of age and health status on this choice. Using the 1998 and 2000 Health and Retirement Study (HRS) and the 2001 HRS Consumption and Activities Mail Survey (CAMS), we estimate a multinomial logit model of older Americans’ choice of vehicle types. We find that both age and health status influence the type of vehicle purchased or leased. Compared to Americans aged 50–59, those aged 70 or older prefer passenger cars to trucks and sport utility vehicles (SUVs). We also find that elders with health problems are more likely to prefer SUVs to passenger cars than those without health problems.

Assessing the risk factors for suicidal thoughts at a nontraditional commuter school

The sample of students completing the National College Health Assessment (NCHA) Survey at the University of Utah differs from the national reference group for the NCHA 2003 in age, employment, residence, and marital status. The purpose of this study is to determine if the defining characteristics of a commuter school increase the risk for suicidal thoughts. During the fall semester of 2004, the University of Utah implemented a randomized electronic survey assessing the student body's health status in several areas. The authors compared 88 respondents who endorsed seriously considered suicide in the previous 12 months were with the remaining 954 respondents to identify discriminating variables. Those students who seriously considered suicide more likely lived off campus, indicated they were emotionally abused, were in only fair health, experienced being assaulted, experienced unwanted sexual touching, or were not heterosexual. Students who were employed were significantly less likely to consider suicide.     

Validating a Behavioral Health Instrument for Adults: Exploratory Factor Analysis

ABSTRACT

Increasingly, social workers and behavioral health practitioners use assessment instruments to support service planning and to monitor progress. Following statewide implementation of the Adult Needs and Strengths Assessment (ANSA) to identify behavioral health symptoms, related functional challenges, risks, and strengths, this validation study explored the underlying structure of the instrument. An exploratory factor analysis used routinely collected information for Midwestern adults with diagnosed behavioral health disorders who participated in community-based services (N = 46,013). Five factors with adequate to good internal consistency (α = 0.733?0.880) emerged: personal recovery, trauma and stress related problems, substance use risks, self-sufficiency, and cultural-linguistic considerations. Validation of the ANSA supports use of the instrument to engage individuals and families, to plan services, to monitor progress, and to conduct research. Implications for social work education, supervision, and practice include the importance of understanding culture, holistic assessment, and services supporting personal recovery for individuals living with mental illness or substance use disorders. Confirmation of findings requires additional research.     

The determinants of the benchmark interest rates in China

This paper empirically investigates the determinants of the two key benchmark interest rates in China using an array of constrained ordered probit models for quarterly frequency data from 1987 to 2013. Specifically, we estimate the behavioral equation of the People's Bank of China that models its decision-making process for revisions of the benchmark deposit rate and the lending rate. Our findings imply that the PBC's policy decisions are better understood as responses to changes in inflation and money growth, while output gaps and the exchange rate play negligible roles. We also implement in-sample fit analyses and out-of-sample forecast exercises. Our empirical findings show robust and reasonably good performances of our models in understanding dynamics of these benchmark interest rates.     

Does social capital always raise life satisfaction? A comparison of South Korea and Taiwan

This study examined the relationship between social capital and life satisfaction in an Asian context, focusing on South Korea and Taiwan. We considered two components of social capital – networks and trust – and argue that the ability of social capital to increase life satisfaction depends on the context. Using the national Life and Society survey data from South Korea (N = 978) and Taiwan (N = 1,200), our analysis found that, when several control variables, such as subjective social status, self‐reported health condition, sex and belief in individualism, were considered, social capital was positively related to life satisfaction in Taiwan, while there was no significant association between social capital and life satisfaction in South Korea. The South Korean case revealed that social capital is not a good predictor of life satisfaction in a context in which being successful is overwhelmingly emphasised.