The role of reversals in order‐restricted inference

A statistical model is said to be an order‐restricted statistical model when its parameter takes its values in a closed convex cone C of the Euclidean space. In recent years, order‐restricted likelihood ratio tests and maximum likelihood estimators have been criticized on the grounds that they may violate a cone order monotonicity (COM) property, and hence reverse the cone order induced by C. The authors argue here that these reversals occur only in the case that C is an obtuse cone, and that in this case COM is an inappropriate requirement for likelihood‐based estimates and tests. They conclude that these procedures thus remain perfectly reasonable procedures for order‐restricted inference.     

Coefficient of variation for the L-class of life distributions

It is shown that the coefficient of variation for the L-class of life distributions is less than or equal to 1.We prove that a d.f. F, belonging to the L-class of life distributions , is exponential if and only if its coefficient of variation is equal to 1.     

The relationship between training outsourcing and employee commitment to organization

In many countries, the human resource practice of training outsourcing has emerged as one of the fastest growing segments of the broader business process outsourcing industry. In spite of the growing popularity in professional practice, training outsourcing continues to be subjected to critical review and ongoing debate with most attention focused on the decision to ‘outsource’ or ‘not to outsource’. However, there exists a shortage of research on training outsourcing as a human resource development (HRD) practice and the potential relationships with desired organizational outcomes including employee commitment. This exploratory international study extends previous research that has examined the relationship between training and organizational commitment by focusing exclusively on outsourced training. Data were collected from information technology firms in two countries: India and the United States. Results showed positive relationships between specific measures of employee perceptions of quality, usefulness and supervisor support for outsourced training with organizational commitment. Recommendations are made for future research as well as for professional practice to guide HRD practitioners involved in the rapidly growing global practice of training outsourcing.     

On an adaptive transformation–retransformation estimate of multivariate location

An affine equivariant estimate of multivariate location based on an adaptive transformation and retransformation approach is studied. The work is primarily motivated by earlier work on different versions of the multivariate median and their properties. We explore an issue related to efficiency and equivariance that was originally raised by Bickel and subsequently investigated by Brown and Hettmansperger. Our estimate has better asymptotic performance than the vector of co-ordinatewise medians when the variables are substantially correlated. The finite sample performance of the estimate is investigated by using Monte Carlo simulations. Some examples are presented to demonstrate the effect of the adaptive transformation–retransformation strategy in the construction of multivariate location estimates for real data.     

A comparison of robust estimators based on two types of trimming

The least trimmed squares (LTS) estimator and the trimmed mean (TM) are two well-known trimming-based estimators of the location parameter. Both estimates are used in practice, and they are implemented in standard statistical software (e.g., S-PLUS, R, Matlab, SAS). The breakdown point of each of these estimators increases as the trimming proportion increases, while the efficiency decreases. Here we have shown that for a wide range of distributions with exponential and polynomial tails, TM is asymptotically more efficient than LTS as an estimator of the location parameter, when they have equal breakdown points.     

Variance estimation with randomized response

Presenting a general procedure of eliciting a randomized response (RR) from selected persons in order to estimate the total of a sensitive variable related to a finite survey population, we consider two estimators along with variance estimators treating the case of sampling with probabilities proportional to (known) size measures (PPS) with replacement (WR), drawing analogies with multi-stage sampling and note their relative efficacies.     

On the Feasibility of Basing Horvitz and Thompson's Estimator on a Sample by Rao,Hartley, and Cochran's Scheme

Formulae for the first and second order inclusion probabilities for the Rao et al. (1962 Rao , J. N. K. , Hartley , H. O. , Cochran , W. G. ( 1962 ). On a simple procedure of unequal probability sampling without replacement . J. Roy. Statist. Soc. B 24 : 482 – 491 . [CSA]  [Google Scholar]) (RHC) scheme of sampling are derived. They enable one to evaluate, for a sample drawn according to the RHC scheme, the Horvitz and Thompson's (1952 Horvitz , D. G. , Thompson , D. J. ( 1952 ). A generalization of sampling without replacement from a finite universe . J. Amer. Statist. Assoc. 47 : 663 – 685 . [CSA] [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) estimator (HTE) along with its unbiased variance estimator given by Yates and Grundy (1953 Yates , F. , Grundy , P. M. ( 1953 ). Selection without replacement from within strata with probability proportional to size . J. Amer. Statist. Assoc. 75 : 206 – 211 . [CSA]  [Google Scholar]). So, for a sample at hand thus drawn one may choose between the RHCE and the HTE for use on finding which one has the smaller coefficient of variation.     

Spillover Impacts of a Reproductive Health Program on Elderly Women in Rural Bangladesh

This paper extends the program evaluation literature by investigating intra-household externalities generated by a reproductive health program, administered as a quasi-control experiment in rural Bangladesh. Although the program targeted only mothers and children in randomly selected treatment areas, using a reduced form demand approach and data from Matlab Health and Socio-economic Survey of 1996, we found a significantly positive spillover impact of this reproductive health program on the health of the never-targeted elderly women.