New procedures for selecting the k-best exponential populations

Suppose exponential populations π_i with parameters (μ_i,σ_i) (i = 1, 2, …, K) are given. The σ_i can be unknown and unequal. This article discusses how to select the k (≥1) best populations. Under the subset selection formulation, a one-stage procedure is proposed. Under the indifference zone formulation, a two-stage procedure is proposed. An appealing feature of these procedures is that no statistical tables are needed for their implementation.     

A stochastic representation for the lp-norm symmetric distribution and its applications

The family of l_p-norm symmetric distributions was proposed by Yue and Ma and is a natural generalization to the family of l₁-norm symmetric distributions studied by Fang et al. In this article, we propose a stochastic representation for the l_p-norm symmetric distribution for any constant p > 0. The stochastic representation is expressed through independent and identically distributed uniform U(0, 1) random variables. It is illustrated that the stochastic representation can be applied to statistical simulation and uniform experimental design.     

Exploring training needs of educational program evaluators in the Asia-Pacific region

Training is critical for the growth of the evaluation profession as more qualified and competent individuals will be required to meet the increased demand for evaluation. This paper deals with the training needs of professionals and is based on a part of a study on the status and challenges of educational program evaluation in the Asia-Pacific region. A web-based Delphi was used with a needs assessment framework for examining the current nature of training, what should be done, and discrepancies (gaps) between the two. The results should be of value for academic training programs and those in non-academic settings.     

Designing and implementing an evaluation of a national work support program

Welfare reforms in the 1990s have shifted governments around the world towards financial assistance conditional on work. While large-scale rigorous research on welfare-to-work programs has demonstrated effectiveness towards employment in other countries, no such micro-level evaluation of a policy has ever been conducted in Singapore. This article describes the process of developing a large experimental evaluation of the Work Support Program, which the Ministry of Community Development, Youth and Sports started in 2006. The lessons learned from planning and implementing the research can be helpful to future researchers in negotiating long-term rigorous evaluations in an environment where collaborators lack sufficient research knowledge. Insights include ways to focus on the essentials, find alternative experimental designs, collaborate effectively, and adapt instruments across cultures.     

Medicaid home- and community-based services: impact of the affordable care act

The Affordable care Act (ACA) legislation of 2010 has three important voluntary provisions for the expansion of home- and community-based services (HCBS) under Medicaid: A state can choose to (1) offer a community first choice option to provide attendant care services and supports; (2) amend its state plan to provide an optional HCBS benefit; and (3) rebalance its spending on long term services and supports to increase the proportion that is community-based. The first and third provisions offer states enhanced federal matching rates as an incentive. Although the new provisions are valuable, the law does not set minimum standards for access to HCBS, and the new financial incentives are limited especially for the many states facing serious budget problems. Wide variations in access to HCBS can be expected to continue, while HCBS will continue to compete for funding with mandated institutional services.     

Change and inertia in the New York state medicaid personal care services program: an institutional case study

This study analyzes how competing logics (belief systems) of stakeholders have influenced patterns of change and inertia in the development of the New York Medicaid Personal Care Services (PCS) program. A case-study methodology was used to collect documents, statistics, and interview data from four key stakeholder groups: state and city officials, PCS agencies, a labor union, and consumer advocates covering the period 1999 to 2005. The New York PCS program is one of the oldest, largest, and most stable programs in the United States. Its early unionization of workers resulted in relatively generous wages and benefits and made New York number one nationally in PCS spending per capita. In spite of wide support from stakeholder groups, the overall number of participants has gradually declined since 1999. A consumer-directed model of personal care developed in 1995 challenged the status quo and has grown steadily. Resistance by public officials, agency providers, and union representatives to the consumer-directed model has resulted in a small program that is often targeted toward individuals labeled "difficult to serve." Dominant stakeholders in New York have ensured a stable personal care program that has resisted change and led to program inertia.     

Which social contacts with natives matter? Attitudes towards gender roles of Muslim immigrants and their children in Western Europe

Social contacts with mainstream individuals play a central role in acculturation. Yet, research has paid little attention to examining whether social contact with natives is linked to egalitarian gender role attitudes among Muslim immigrants and their children. Using a unique data set including 4584 Muslim immigrants and the second generation in six western European countries (EURISLAM), the study investigates whether public- and private-sphere social contacts with natives are associated with attitudes towards women's employment and men's domestic roles. The findings show that immigrants and their children who report stronger private-sphere social ties, that is native friends and family members, hold more egalitarian attitudes towards women's employment and men's domestic roles. However, public-sphere social contacts (at the workplace and in the neighbourhood) are not associated with these attitudes. These results support theories stating that private-sphere social contact with natives is important in gender role ideology acculturation among Muslim families.     

LAG Length Selection and the Construction of Unit Root Tests with Good Size and Power

It is widely known that when there are errors with a moving‐average root close to −1, a high order augmented autoregression is necessary for unit root tests to have good size, but that information criteria such as the AIC and the BIC tend to select a truncation lag (k) that is very small. We consider a class of Modified Information Criteria (MIC) with a penalty factor that is sample dependent. It takes into account the fact that the bias in the sum of the autoregressive coefficients is highly dependent on k and adapts to the type of deterministic components present. We use a local asymptotic framework in which the moving‐average root is local to −1 to document how the MIC performs better in selecting appropriate values of k. In Monte‐Carlo experiments, the MIC is found to yield huge size improvements to the DF^GLS and the feasible point optimal P_T test developed in Elliott, Rothenberg, and Stock (1996). We also extend the M tests developed in Perron and Ng (1996) to allow for GLS detrending of the data. The MIC along with GLS detrended data yield a set of tests with desirable size and power properties.     

Patterns In Discourse About Elderly People In New Zealand

As the number of senior citizens continues to rise, their public profile will grow and political discussion about their future will become increasingly prominent. The present research was designed to approach such debate by providing an assay of naturally occurring data drawn from the New Zealand Royal Commission on Social Policy (1986–1988). Public submissions to the Royal Commission on the specific subject of senior citizens were extracted and examined from a discourse analytic perspective. The results obtained by two independent analyses showed three patterns of discourse, namely, society's obligations to senior citizens, anti-ageism, and old age as a positive resource. This troika of discourse patterns constitute a collective voice through which senior citizens and their supporters defend and advocate the social position of senior citizens.     

Nonparametric methodology for the time-dependent partial area under the ROC curve

To assess the classification accuracy of a continuous diagnostic result, the receiver operating characteristic (ROC) curve is commonly used in applications. The partial area under the ROC curve (pAUC) is one of the widely accepted summary measures due to its generality and ease of probability interpretation. In the field of life science, a direct extension of the pAUC into the time-to-event setting can be used to measure the usefulness of a biomarker for disease detection over time. Without using a trapezoidal rule, we propose nonparametric estimators, which are easily computed and have closed-form expressions, for the time-dependent pAUC. The asymptotic Gaussian processes of the estimators are established and the estimated variance-covariance functions are provided, which are essential in the construction of confidence intervals. The finite sample performance of the proposed inference procedures are investigated through a series of simulations. Our method is further applied to evaluate the classification ability of CD4 cell counts on patient's survival time in the AIDS Clinical Trials Group (ACTG) 175 study. In addition, the inferences can be generalized to compare the time-dependent pAUCs between patients received the prior antiretroviral therapy and those without it.