Orthodox BLUP versus h-likelihood methods for inferences about random effects in Tweedie mixed models

Recently, the orthodox best linear unbiased predictor (BLUP) method was introduced for inference about random effects in Tweedie mixed models. With the use of h-likelihood, we illustrate that the standard likelihood procedures, developed for inference about fixed unknown parameters, can be used for inference about random effects. We show that the necessary standard error for the prediction interval of the random effect can be computed from the Hessian matrix of the h-likelihood. We also show numerically that the h-likelihood provides a prediction interval that maintains a more precise coverage probability than the BLUP method.     

Implementation of JIT purchasing: An integrated approach

This article addresses the necessity of integration between buyer and supplier for effective implementation of the JIT system. An integrated lot-splitting model of facilitating multiple shipments in small lots is developed and compared with the existing approach in a simple JIT environment, single-buyer-single-supplier, under deterministic conditions for a single product. It is shown that the optimal policy adopted by the integrated approach can provide a strong and consistent cost-minimizing effect for both buyer and supplier over the existing approach.     

Sustainable landscaping programs in the United States and their potential to encourage conservation and support ecosystem services

Sustainable landscaping programs are voluntary initiatives that recommend a set of practices to improve the environmental quality of urban ecosystems by providing landscaping materials, guidelines, and educational resources. Our goal was to examine the recommendations and outcomes of these programs in the United States and their value for encouraging conservation practices in residential ecosystems. We conducted a comprehensive web search and identified 193 sustainable landscaping programs in the United States. Programs aim to increase native species richness, affordably manage stormwater runoff, and offer residents meaningful experiences with nature. Sustainable landscaping programs present many opportunities to engage people with local ecological knowledge and conservation practices, provide accessible spaces for environmental education, cultivate interdisciplinary research collaborations, and advance inclusion in conservation. However, assessments of their ecological value are rare, leaving many questions surrounding the benefits to biodiversity and water quality afforded by participation. Many programs also require investments in landscaping materials and certification fees that might limit participation by some households. Future work should examine how recommended practices influence urban biodiversity, identify and address barriers to participation, and generate social-ecological knowledge that can inform future programs.

     

Personality and Subjective Well-Being: Evidence from South Korea

Although the statistically significant relationship between personality traits and subjective well-being (i.e., self-reported happiness and life satisfaction) is well-known in the field of positive psychology, some scholars still cast doubt on the external validity of this finding and the strength of personality dimensions vis-à-vis other individual-level determinants of subjective well-being such as income, employment status, marital status, self-reported health, and so on. Using a nationally representative, face-to-face survey fielded in South Korea in 2009, we find that personality traits (measured by the Five-factor Model)—particularly, Emotional Stability and Extraversion—are positively associated with happiness and life satisfaction, after controlling for other covariates. The effects of personality traits are often on par with, and sometimes even greater than, those of other well-known determinants.     

On the asymptotic behaviour of the recursive Nadaraya–Watson estimator associated with the recursive sliced inverse regression method

We investigate the asymptotic behaviour of the recursive Nadaraya–Watson estimator for the estimation of the regression function in a semiparametric regression model. On the one hand, we make use of the recursive version of the sliced inverse regression method for the estimation of the unknown parameter of the model. On the other hand, we implement a recursive Nadaraya–Watson procedure for the estimation of the regression function which takes into account the previous estimation of the parameter of the semiparametric regression model. We establish the almost sure convergence as well as the asymptotic normality for our Nadaraya–Watson estimate. We also illustrate our semiparametric estimation procedure on simulated data.     

Information fraction estimation: Strategies for a phase 3 non-inferiority maximum duration design with time to event outcome

There is considerable debate surrounding the choice of methods to estimate information fraction for futility monitoring in a randomized non-inferiority maximum duration trial. This question was motivated by a pediatric oncology study that aimed to establish non-inferiority for two primary outcomes. While non-inferiority was determined for one outcome, the futility monitoring of the other outcome failed to stop the trial early, despite accumulating evidence of inferiority. For a one-sided trial design for which the intervention is inferior to the standard therapy, futility monitoring should provide the opportunity to terminate the trial early. Our research focuses on the Total Control Only (TCO) method, which is defined as a ratio of observed events to total events exclusively within the standard treatment regimen. We investigate its properties in stopping a trial early in favor of inferiority. Simulation results comparing the TCO method with alternative methods, one based on the assumption of an inferior treatment effect (TH0), and the other based on a specified hypothesis of a non-inferior treatment effect (THA), were provided under various pediatric oncology trial design settings. The TCO method is the only method that provides unbiased information fraction estimates regardless of the hypothesis assumptions and exhibits a good power and a comparable type I error rate at each interim analysis compared to other methods. Although none of the methods is uniformly superior on all criteria, the TCO method possesses favorable characteristics, making it a compelling choice for estimating the information fraction when the aim is to reduce cancer treatment-related adverse outcomes.     

Impact of internal migration on the economic well-being of local workers and school dropouts among children in Vietnam

This study examines the impact of migration on local workers and high school dropouts of local students. A conventional approach without addressing the endogeneity issue may lead to biased results. Our endogeneity-corrected estimates show a positive impact of migration on the monthly wages of local workers. A higher share of migrants increases the probability of local workers with employment contracts, social insurance, and holiday pay. Heterogeneity analysis shows that local workers, no matter their educational level, work experience, or occupation sectors, benefit from the inflow of migrants. Finally, migration inflow lowers the probability of high school dropouts among local students. Our findings resulting from rigorous statistical approaches suggest that internal migration produces positive impacts on the economic well-being of local residents, refuting the argument about the adverse effects associated with internal migration.     

Who governs or how they govern: Testing the impact of democracy,ideology and globalization on the well being of the poor

This paper examines the effects of regime type, government ideology and economic globalization on poverty in low- and middle-income countries around the world. We use panel regression to estimate the effect of these explanatory variables on two different response variables: national poverty gap (104 countries from 1981 to 2005) and child mortality rate (132 countries from 1976 to 2005). We find consistent and significant results for the interactive effect of democracy and government ideology: strong leftist power under a democratic regime is associated with a reduction in both the poverty gap and the child mortality rate. Democracy, on its own, is associated with a lower child mortality rate, but has no effect on the poverty gap. Leftist power under a non-democratic regime is associated with an increase in both poverty measures. Trade reduces both measures of poverty. Foreign direct investment has a weak and positive effect on the poverty gap. From examining factors that influence the welfare of poor people in less developed countries, we conclude that who governs is as important as how they govern.     

The Past in the Present. Lessons on Semiotics of History from George H. Mead and Boris A. Uspensky

This article examines the parallels between George H. Mead's theory of time and Boris A. Uspensky's semiotics of history, looking for implications relevant to the symbolic interactionist theory of historical processes. It suggests that Mead's theory of time and theory of communication hold important implications for semiotic analysis of the historical dimension of sociocultural phenomena. A further aim is to link the symbolic interactionist tradition of the Chicago school with the Tartu school and its semiotics of history. This would fuel the further development of both theoretical orientations.     

Tolerance of Uncertainty: Links to Happenstance,Career Decision Self‐Efficacy,and Career Satisfaction

This study investigated the extent to which tolerance of uncertainty affects the relationship between happenstance skills and career satisfaction via career decision self‐efficacy. Moderated mediation analysis was conducted on data collected from 321 graduates (175 men, 146 women) of Korean universities making the school‐to‐work transition. Results showed that career decision self‐efficacy fully mediated the relationship between happenstance skills and career satisfaction. Furthermore, the moderation effect of tolerance of uncertainty had a significant impact on the relationship between happenstance skills and career decision self‐efficacy. Tolerance of uncertainty should be considered an important variable in happenstance career theory and intervention. Unplanned influences should also be considered important factors in the career decision‐making process.