Preliminary test estimators of the parameters of simple linear model with measurement error

In this paper, we discuss the properties of preliminary test estimators (PTE) of the parameters of simple linear model with measurement error (ME model) when the slope of the linear model is suspected to be zero. Expressions of the bias, MSE and efficiencies are obtained under conditional as well as unconditional situations with known reliability coefficient. Conditional model results are compared to the standard model without measurement error. We also provide the unconditional model analysis in finite samples. Asymptotic theory under local alternatives is developed when the variance of measurement error or the ratio of the variance of the model error relative to the variance of the measurement error is known. Asymptotic expressions of bias and MSE of the estimators along with their efficiencies are obtained. In every case, it is shown that the measurement error tend to increase the variability of the estimators compared to the estimators without measurement error. Graphs and tables are provided to see these results and to determine optimum level of significance for minimum guaranteed efficiency. Received October 2001 RID="*" ID="*"  A. K. Md. E. Saleh is a Distinguished Research Professor and H. M. Kim is a Ph.D. candidate in the School of Mathematics and Statistics, Carleton University, Ottawa. Acknowledgment. The authors gratefully acknowledge the constructive suggestion of the referees to improve the paper. The research is supported by NSERC grant A3088.     

A CROSS-NATIONAL STUDY OF LEADERSHIP: PARTICIPATION AS A FUNCTION OF PROBLEM STRUCTURE AND LEADER POWER

This study explores the effects of task structure and leader power on participative leadership across Australian, African, Papua-New Guinea and Pacific Island managers. Managers in all national groups are more participative in situations of low structure and low power than for high structure and high power, respectively. Participation in situations of low structure and low power declines in the order: Australia, Africa, Papua-New Guinea, Pacific Islands. It is argued that this effect is an instrumental effect of managerial education, rather than being culturally determined. the Vroom-Yetton leadership methodology is used to measure participation levels. Subjects are a total of 150 middle-level managers attending management education courses.     

Status Implications of the Employment of Married Women in the United States

Abstract: The working wife as a factor in the determination of family status has been universally ignored by students of stratification. In this plea for investigation, it is suggested that the employment or married women could affect the system of stratification in the following ways: (1) making possible greater access to symbols of status; (2) implying that the husband has been unsuccessful in his own career; (3) identifying the wife with a particular occupation; and (4) identifying certain occupations with wives of high status.     

Sample Design and Allocation for Random Digit Dialling

Sample design and sample allocation methods are developed for random digit dialling in household telephone surveys. The proposed method is based on a two-way stratification of telephone numbers. A weighted probability proportional to size sample allocation technique is used, with auxiliary variables about the telephone coverage rates, within local telephone exchanges of each substrata. This makes the sampling design nearly “self-weighting” in residential numbers when the prior information is well assigned. A computer program generates random numbers for the local areas within the existing phone capacities. A simulation study has shown greater sample allocation gain by the weighted probabilities proportional to size measures over other sample allocation methods. The amount of dialling required to obtain the sample is less than for proportional allocation. A decrease is also observed on the gain in sample allocation for some methods through the increasing sample sizes.     

Progressive stress accelerated life tests under finite mixture models

In this paper, progressive stress accelerated life tests are considered when the lifetime of a product under use condition follows a finite mixture of distributions. The experiment is performed when each of the components in the mixture follows a general class of distributions which includes, among others, the Weibull, compound Weibull, power function, Gompertz and compound Gompertz distributions. It is assumed that the scale parameter of each component satisfies the inverse power low, the progressive stress is directly proportional to time and the cumulative exposure model for the effect of changing stress holds. Based on type-I censoring, the maximum likelihood estimates (MLEs) of the parameters under consideration are obtained. A special attention is paid to a mixture of two Rayleigh components. Simulation results are carried out to study the precision of the MLEs and to obtain confidence intervals for the parameters involved.     

Canadian and American Reactions to Drug and Alcohol Testing Programs in the Workplace

We investigated U.S. and Canadian reactions to workplace drug and alcohol testing programs. Canadian truck drivers (n = 183) deemed drug and alcohol testing policies less fair, and were less accepting of these policies, than their American counterparts (n = 153). We also compared the perspectives of recipients versus third-party observers with regard to their reactions to a drug testing program. Unlike the pattern observed among American observers, the responses by Canadian observers were highly similar to those of the recipients. Canadian observers were more inclined to file a formal protest regarding the implementation of a drug and alcohol testing program than were U.S. observers. The results also showed that procedural and interactional justice principles contributed to the program's fairness, acceptance, and lower levels of protest intentions in both Canada and the United States. We propose that scholars and practitioners can gain a better understanding of multinational reactions to drug and alcohol testing by considering not only cultural but also historical, social, political, and other environmental factors that can shape reactions to personnel practices.     

An effective step-down algorithm for the construction and the identification of nonisomorphic orthogonal arrays

In this paper we present an effective algorithm for the construction and the identification of two-level nonisomorphic orthogonal arrays. Using this algorithm, we identify and list a full catalogue of nonisomorphic orthogonal arrays with parameters OA(24,7,2,t), OA(28,6,2,t) and OA(32,6,2,t), t ≥ 2. Some statistical properties of these designs are also considered.     

When haste makes sense: Cracking down on street markets for illicit drugs

This paper presents an analytical approach to the tactical question: ‘What level of enforcement over time allows one to eliminate a street market for illicit drugs while expanding the least possible total effort?’ The analysis is done in the context of Caulkins' model [6] which predicts the rate of change of dealers as a function of enforcement level and several market parameters. Our analysis suggests that the simple strategy of using the maximum available enforcement intensity until the market has been eliminated minimizes the total enforcement effort required.     

Designs for estimating an extremal point of quadratic regression models in a hyperball

This paper is devoted to studying optimal designs for estimating an extremal point of a multivariate quadratic regression model in the unit hyperball. The problem of estimating an extremal point is reduced to that of estimating certain parameters of a corresponding nonlinear (in parameters) regression model. For this reduced problem truncated locally D-optimal designs are found in an explicit form. The result is a generalization of the results of Fedorov and Müller (1997) for onedimensional quadratic regression function in the unit segment. Received February 2002     

Selecting Sites for New Facilities Using Data Envelopment Analysis

This paper develops a mathematical programming model for obtaining a best set of sites for planned facilities. The model is concerned with those situations where resource constraints are present. The specific setting for the paper involves the selection of sites for a set of retail outlets, wherein the ratio of aggregate outputs to inputs for the selected set is maximal among all possible sets that could be chosen. At the same time, the model guarantees that the only sets of stores allowable are those for which the available resources are used to the maximum extent possible.