Tests for the skewness parameter of two-piece double exponential distribution in the presence of nuisance parameters

In this paper, tests for the skewness parameter of the two-piece double exponential distribution are derived when the location parameter is unknown. Classical tests like Neyman structure test and likelihood ratio test (LRT), that are generally used to test hypotheses in the presence of nuisance parameters, are not feasible for this distribution since the exact distributions of the test statistics become very complicated. As an alternative, we identify a set of statistics that are ancillary for the location parameter. When the scale parameter is known, Neyman–Pearson's lemma is used, and when the scale parameter is unknown, the LRT is applied to the joint density function of ancillary statistics, in order to obtain a test for the skewness parameter of the distribution. Test for symmetry of the distribution can be deduced as a special case. It is found that power of the proposed tests for symmetry is only marginally less than the power of corresponding classical optimum tests when the location parameter is known, especially for moderate and large sample sizes.     

Reducing child abuse through respite center intervention

Emergency respite care for children is shown to be effective in reducing stress on parents that can result in child abuse.     

Compliance Strategies under Permits for Emissions

We characterize the trade‐offs among firms' compliance strategies in a market‐based program where a regulator interested in controlling emissions from a given set of sources auctions off a fixed number of emissions permits. We model a three‐stage game in which firms invest in emissions abatement, participate in a share auction for permits, and produce output. We develop a methodology for a profit‐maximizing firm to derive its marginal value function for permits and translate this value function into an optimal bidding strategy in the auction. We analyze two end‐product market scenarios independent demands and Cournot competition. In both scenarios we find that changing the number of available permits influences abatement to a lesser extent in a dirty industry than in a cleaner one. In addition, abatement levels taper off with increasing industry dirtiness levels. In the presence of competition, firms in a relatively clean industry can, in fact, benefit from a reduction in the number of available permits. Our findings are robust to changes in certain modeling assumptions.     

Tests for symmetry of two-piece normal distribution

In this paper, classical optimum tests for symmetry of two-piece normal distribution is derived. Uniformly most powerful one-sided test for the skewness parameter is obtained when the location and scale parameters are known and is compared with sequential probability ratio test. An ad-hoc test for symmetry and likelihood ratio test for symmetry for large samples, can be found in literature for this distribution. But in this paper, we derive exact likelihood ratio test for symmetry, when location parameter is known. The exact power of the test is evaluated for different sample sizes.     

The Selection of Computer-Aided Software Engineering Tools: A Multi-Criteria Decision Making Approach

The selection of the appropriate computer-aided software engineering (CASE) tools to suit the needs of an organization requires the systematic application of the multi-criteria decision methodology (MCDM). In order to make a case for the use of MCDM, the application of the ELECTRE I method to the selection of CASE tools from a possible set of six alternatives is demonstrated. The demonstration helps in gaining a grasp of the MCDM approach and the ELECTRE I method. There is potential for the application of the MCDM approach in other software engineering decisions, especially in the feasibility analysis of the systems life cycle.     

Function-based hypothesis testing in censored two-sample location-scale models

Function-based hypothesis testing in two-sample location-scale models has been addressed for uncensored data using the empirical characteristic function. A test of adequacy in censored two-sample location-scale models is lacking, however. A plug-in empirical likelihood approach is used to introduce a test statistic, which, asymptotically, is not distribution free. Hence for practical situations bootstrap is necessary for performing the test. A multiplier bootstrap and a model appropriate resampling procedure are given to approximate critical values from the null asymptotic distribution. Although minimum distance estimators of the location and scale are deployed for the plug-in, any consistent estimators can be used. Numerical studies are carried out that validate the proposed testing method, and real example illustrations are given.

     

The relationship between supply chain manager capabilities and performance: empirical evidence

This study seeks to answer the question how supply chain managers’ capabilities impact individual and firm performance. Organisations have begun to recognise the importance of their supply chain and the necessity for qualified supply chain managers. Therefore, there is a need for further research on the impact of these capabilities on individual and firm performance. Sustained performance of a firm depends on dynamic capabilities and it allows firms to align and adapt strategies according to the volatile external environment. Using dynamic capabilities theory, the supply chain manager capabilities model was developed as a way for supply chain managers to effectively use their skills and past experiences to improve their own and firm’s performance. Primary data was collected through a survey distributed to supply chain management professionals. The results strongly support the relationship between technology and soft skills with supply chain manager capabilities. Interestingly, our study identifies sequential relationship amongst the three constructs such as capabilities, individual and firm performance. Capabilities are related with individual performance whereas individual performance is related with the firm performance. However, our findings revealed that there is no direct relationship between supply chain manager capabilities and firm performance.     

Being well and doing well: on the importance of income for health

Income is robustly associated with health status. Higher income is associated with lower mortality and morbidity, both cross-nationally and within societies. This relationship is not just confined to low levels of income, but extends well beyond median levels of income in society with diminishing marginal returns to health status with additional increments in income. Drawing upon the absolute and relative interpretations of income and conceptualising them simul-taneously at the individual and community level, we develop a typology of income–health relationships and discuss the distinctiveness of, and connections between, each type. We conclude that a multilevel conceptual and methodological framework is most appropriate to understand the income–health relationship.     

Notes on Contributors

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