Bayesian False Discovery Rate Wavelet Shrinkage: Theory and Applications

Statistical inference in the wavelet domain remains a vibrant area of contemporary statistical research because of desirable properties of wavelet representations and the need of scientific community to process, explore, and summarize massive data sets. Prime examples are biomedical, geophysical, and internet related data. We propose two new approaches to wavelet shrinkage/thresholding.

In the spirit of Efron and Tibshirani's recent work on local false discovery rate, we propose Bayesian Local False Discovery Rate (BLFDR), where the underlying model on wavelet coefficients does not assume known variances. This approach to wavelet shrinkage is shown to be connected with shrinkage based on Bayes factors. The second proposal, Bayesian False Discovery Rate (BaFDR), is based on ordering of posterior probabilities of hypotheses on true wavelets coefficients being null, in Bayesian testing of multiple hypotheses.

We demonstrate that both approaches result in competitive shrinkage methods by contrasting them to some popular shrinkage techniques.     

A Regression Model for the AUC of Clustered Ordinal Test Results and Working Independent Optimal Weights

We study a regression model on the area under the receiver operating characteristic curves (AUC) for clustered (or repeatedly measured) test results. To account for cluster information, we consider a weighted estimating equation for Dodd and Pepe (2003 Dodd , L. , Pepe , M. ( 2003 ). Semiparametric regression for the area under the receiver operating charateristic curve . Journal of the American Statistical Association 98 : 409 – 417 .[Taylor & Francis Online], [Web of Science ®] , [Google Scholar])'s regression model with working independence weights. We find the optimal weight in the given class of working independence weights to minimize the variance (or MSE) of regression estimators. We apply the proposed procedure to analyzing our recent experiment on diagnosing a liver disorder. In this experiment, we investigated MRI images of patients having symptoms of potential liver disorder to compare the performance of different MRI picturing methods in testing for liver disorders.     

Homelessness and Children's Use of Mental Health Services: A Population-Based Study

This study examined whether children who become homeless differ from other low-income children in their mental health service use before and after their first homeless episode, and to what extent homelessness is associated with an increased likelihood of mental health service use. Differences between children with and without new onset of sheltered homelessness in the use of mental health services emerged following homelessness and widened over time. Sheltered homelessness and foster care placement history were associated with increased odds of receiving inpatient and ambulatory mental health services. Findings underscore the importance of collaborations between homeless assistance, foster care, and mental healthcare in efforts to mitigate family homelessness and collateral needs among homeless children.     

Bending but Not Breaking?: Foreign Investor Pressure and Dividend Payouts by Japanese Firms

This article examines the global diffusion of shareholder‐oriented governance practices, using the case of dividend payouts by Japanese firms. While Japanese firms previously retained profits for rainy days or new ventures, their dividend payouts began to increase in the 1990s, rapidly catching up with the levels prevailing in the United States. Following prior research, we focus on the role of foreign investors in this process but provide a more nuanced account of their influence, using panel data on 2,036 publicly traded Japanese firms from 1990 to 2005. First, we show that pressure from foreign investors increased dividends by Japanese firms not only directly but also indirectly, by extending the cognitive boundaries of organizational fields of Japanese firms beyond their local peers and toward their global competitors. Second, we show that although Japanese firms that remained deeply embedded in the traditional, stakeholder‐oriented governance system resisted shareholder‐oriented governance practices, even such firms yielded under pressure from both foreign and domestic investors. We conclude with theoretical implications of our findings for the literature on the global diffusion of shareholder value and its broader political and social consequences.     

A Moderated Mediation Model of Planned Happenstance Skills,Career Engagement,Career Decision Self‐Efficacy,and Career Decision Certainty

This study examined how college students’ levels of planned happenstance skills influenced the relationships among career engagement, career decision self‐efficacy, and career decision certainty. Moderated mediation analysis was used with a sample of 217 Korean undergraduate students. The results indicated that career decision self‐efficacy mediated the relationship between career engagement and career decision certainty. Moreover, the positive indirect effect of career engagement on career decision through career decision self‐efficacy was strengthened as the level of planned happenstance skills increased. In conclusion, college students’ career engagement strengthens their career decision certainty via career decision self‐efficacy when they have enough planned happenstance skills to discover unexpected career opportunities.     

Construction and Initial Validation of the Planned Happenstance Career Inventory

This study was conducted to develop and initially evaluate the psychometric properties of the Planned Happenstance Career Inventory (PHCI), which aims to assess skill in using chance events to develop career opportunities. After item generation and exploratory factor analysis, 130 original items were reduced to 25 items across 5 factors (5 items for each corresponding factor). Multigroup confirmatory factor analysis confirmed the validity of this 5‐factor structure, and the goodness of fit showed an adequate fit to the observed data for both women and men. Results showed that PHCI subscales correlated moderately and in expected directions with career preparation, career decision‐making self‐efficacy, and career stress. These findings suggest that the PHCI, which assesses 5 dimensions of career‐related planned happenstance skill, shows promise as a useful tool for facilitating understanding of the influence of chance events on career choice behavior.     

Disability discrimination in South Korea: routine and everyday aggressions toward disabled people

In the past, the type of discrimination against persons with disabilities in South Korea was seen mainly as being related to the physical environment and social systems that ignored disability. However, the emergence of social model and anti-discrimination laws established in numerous countries has rapidly expanded the scope of social participation for persons with disabilities as well as their awareness of their rights. This article posits that a type of disability discrimination that could emerge in the future is microaggression, which can appear in diverse forms in newly formed human relationships as the scope of social participation increases.     

A MACROECONOMIC ANALYSIS OF ENERGY SUBSIDIES IN A SMALL OPEN ECONOMY

We construct a dynamic model of a small open economy to analyze the effects of large energy subsidies. The model includes domestic energy production and consumption, trade in energy at world market prices, as well as private and public sector production. The model is calibrated to Egypt and used to study reforms such as reductions in energy subsidies with corresponding reductions in various tax instruments or increases in infrastructure investment. We calculate the new steady states, transition paths to the new steady state, and the size of the associated welfare losses or gains. Our main results for a 15% cut in energy subsidies are: (1) Steady state gross domestic product drops in most of our experiments as less energy is used in production. (2) Steady state consumption rises in most of our experiments. (3) Welfare can rise by as much as 0.6% in consumption equivalent terms. (4) The largest gains in terms of output and of welfare can be obtained when savings from energy subsidy cuts are used to fund additional infrastructure investment. (JEL E21, E63, H55, J26, J45)     

Theoretical properties of tests for spatial clustering of count data

Testing for spatial clustering of count data is an important problem in spatial data analysis. Several procedures have been proposed to this end but despite their extensive use, studies of their fundamental theoretical properties are almost non‐existent. The authors suggest two conditions that any reasonable test for spatial clustering should satisfy. The latter are based on the notion that the null hypothesis should be rejected almost surely as the amount of spatial clustering tends to infinity. The authors show that the chisquared test and the Potthoff—Whittinghill V have both properties but that other classical tests do not.     

Robust Bayesian estimation of a two-parameter exponential distribution under generalized Type-I progressive hybrid censoring

A generalized Type-I progressive hybrid censoring scheme was proposed recently to overcome the limitations of the progressive hybrid censoring scheme. In this article, we provide a robust Bayesian method to estimate the unknown parameters of the two-parameter exponential distribution of a generalized Type-I progressive hybrid censored sample. For each parameter, we derive the marginal posterior density functions and the corresponding Bayesian estimators under the squared error loss function. To assess the proposed method, Monte Carlo simulations are performed using a real dataset.