Comparison of preliminary test estimators based on generalized order statistics from proportional hazard family using Pitman measure of closeness

In this article, based on generalized order statistics from a family of proportional hazard rate model, we use a statistical test to generate a class of preliminary test estimators and shrinkage preliminary test estimators for the proportionality parameter. These estimators are compared under Pitman measure of closeness (PMC) as well as MSE criteria. Although the PMC suffers from non transitivity, in the first class of estimators, it has the transitivity property and we obtain the Pitman-closest estimator. Analytical and graphical methods are used to show the range of parameter in which preliminary test and shrinkage preliminary test estimators perform better than their competitor estimators. Results reveal that when the prior information is not too far from its real value, the proposed estimators are superior based on both mentioned criteria.     

Education and Employment among Muslims in Indian Jammu and Kashmir

Muslims constitute about 14% population of India and are the largest religious minority community spread over the length and breadth of the country. The minority community in question has been relegated to the lowest socio-economic stratum in Indian society especially after the partition and independence of the country. However, in the state of Jammu and Kashmir, Muslims are in majority constituting about 67% population of the state. In the current study, the Concentration Index of Muslim population, variation in literacy rate and work participation, occupational structure across region and religion, as well as the interrelationship between concentration of Muslim population, literacy rate and work participation in Jammu and Kashmir has been explored and explained. The present study is based upon secondary information obtained from Census 2001 and is also supplemented with government reports, published work wherever necessary. As far as share of Muslims in the sphere of education and employment in the state of Jammu and Kashmir is concerned, they have reported lower share among the population of literates, category of other workers and higher share in the occupational category of cultivators, agricultural labourers, household industry workers and non-workers in comparison to all religious groups. This means that despite being in majority, their situation is similar to their co-religionists at the all India level.     

… Do as the Romans do. A model of conformity with the endogenous formation of preferences

This note is an answer to a previous model on conformity in public goods contributions developed by Carpenter (2004), where a population evolution is allowed according to the standard replicator dynamic (Taylor and Jonker, 1978, Maynard Smith, 1982). To confirm his theoretical prediction, Carpenter developed an experiment showing that free riding actually grows faster when agents have the information necessary to conform. The model and the experiment are, however, inherently different, for the time scales of the model are not able to capture the short run convergence of behavior in the experimental laboratory.We here present a model of conformity which offers the same laboratory results as Carpenter without resorting to evolutionary models, and also gives agents the chance to adopt different strategies implying various levels of cooperation.     

Supply chain agility as an acclimatisation process to environmental uncertainty and organisational vulnerabilities: insights from British SMEs

Abstract

Even though supply chain agility (SCA) has been considered an essential concept in supply chain management (SCM) research, the way it is experienced and manifested, especially by small and medium-sized enterprises (SMEs), has received much less attention. Our purpose is to focus on SME organisational vulnerabilities in the context of increased environmental uncertainty, and explore how SCA is developed and applied by SMEs amid their vulnerabilities. By relying on insights from comparative case studies of three British SMEs, we examine SME SCA as an acclimatisation process and delve into SMEs’ experiences of facing environmental uncertainty while developing and applying SCA. Our findings highlight that organisational attitudes underlie how SMEs perceive environmental uncertainty, tackle organisational vulnerabilities and develop SCA as an acclimatisation process. Our findings also reveal that resource constraints, supply chain relationships, interorganisational power dynamics, and access to information play important roles in developing SCA.     

Four Motives for Community Involvement

A conceptual analysis is offered that differentiates four types of motivation for community involvement: egoism, altruism, collectivism, and principlism. Differentiation is based on identification of a unique ultimate goal for each motive. For egoism, the ultimate goal is to increase one's own welfare; for altruism, it is to increase the welfare of another individual or individuals; for collectivism, to increase the welfare of a group; and for principlism, to uphold one or more moral principles. As sources of community involvement, each of these four forms of motivation has its strengths; each also has its weaknesses. More effective efforts to stimulate community involvement may come from strategies that orchestrate motives so that the strengths of one motive can overcome weaknesses of another. Among the various possibilities, strategies that combine appeals to either altruism or collectivism with appeals to principle may be especially promising.     

Testing variance components in balanced linear growth curve models

It is well known that the testing of zero variance components is a non-standard problem since the null hypothesis is on the boundary of the parameter space. The usual asymptotic chi-square distribution of the likelihood ratio and score statistics under the null does not necessarily hold because of this null hypothesis. To circumvent this difficulty in balanced linear growth curve models, we introduce an appropriate test statistic and suggest a permutation procedure to approximate its finite-sample distribution. The proposed test alleviates the necessity of any distributional assumptions for the random effects and errors and can easily be applied for testing multiple variance components. Our simulation studies show that the proposed test has Type I error rate close to the nominal level. The power of the proposed test is also compared with the likelihood ratio test in the simulations. An application on data from an orthodontic study is presented and discussed.     

Bayesian and Robust Bayesian analysis under a general class of balanced loss functions

For estimating an unknown parameter θ, we introduce and motivate the use of balanced loss functions of the form L_{r, w, d0}(q, d)=wr(d₀, d)+ (1-w) r(q, d){L_{rho, omega, delta_0}(theta, delta)=omega rho(delta_0, delta)+ (1-omega) rho(theta, delta)}, as well as the weighted version q(q) L_{r, w, d0}(q, d){q(theta) L_{rho, omega, delta_0}(theta, delta)}, where ρ(θ, δ) is an arbitrary loss function, δ ₀ is a chosen a priori “target” estimator of q, w ? [0,1){theta, omega in[0,1)}, and q(·) is a positive weight function. we develop Bayesian estimators under L_{r, w, d0}{L_{rho, omega, delta_0}} with ω > 0 by relating such estimators to Bayesian solutions under L_{r, w, d0}{L_{rho, omega, delta_0}} with ω = 0. Illustrations are given for various choices of ρ, such as absolute value, entropy, linex, and squared error type losses. Finally, under various robust Bayesian analysis criteria including posterior regret gamma-minimaxity, conditional gamma-minimaxity, and most stable, we establish explicit connections between optimal actions derived under balanced and unbalanced losses.     

Economic burden of tuberculosis and its coping mechanism at the household level in Pakistan

Despite the availability of free medicines under the Directly Observed Treatment Short-course (DOTS) strategy, the treatment of tuberculosis (TB) still involves high costs that push people into poverty. This study aims to assess the resulting economic burden of TB and examine the coping mechanisms practiced at the household level in Pakistan. A cross-sectional study was conducted at TB centers by interviewing 269 patients. Statistical tests and binary logistic regression were used to explore the relationship between catastrophic health expenditures (CHE) and socio-economic factors. Results show that the incidence and intensity of CHE were higher for households in the lower income-quintile. Several coping strategies were practiced and varied among the different income-quintiles. The independent determinants of CHE were as follows: age >40 years, male-patient, location, earner-ratio, patient as the earner, caretaker visits, treatment delay, and co-morbidity. It is recommended that health policymakers develop post-MDGs TB-control strategies to ensure free TB-services with financial protection around the globe.     

Information matrix for a mixture of two inverse gaussian distributions

In this paper, Fisher information matrix about the five parameters ρ, μ_:1, μ², λ¹and λ²of a mixture of two Inverse Gaussian density functions is obtained. The Leguerre-Gauss quadrature formula is used to evaluate the essential integral on which the twenty five elements of the information matrix are based. Results involving the computation of the information about p are compared with those involving both the power series expansion and Simpson's method of integration. Laguerre-Gauss quadra-ture was found to lead to good approximations as compared with other methods. It was therefore chosen for the computations of the elements of the information matrix.