Joint confidence regions in the multivariate calibration problem

Consider a vector valued response variable related to a vector valued explanatory variable through a normal multivariate linear model. The multivariate calibration problem deals with statistical inference on unknown values of the explanatory variable. The problem addressed is the construction of joint confidence regions for several unknown values of the explanatory variable. The problem is investigated when the variance covariance matrix is a scalar multiple of the identity matrix and also when it is a completely unknown positive definite matrix. The problem is solved in only two cases: (i) the response and explanatory variables have the same dimensions, and (ii) the explanatory variable is a scalar. In the former case, exact joint confidence regions are derived based on a natural pivot statistic. In the latter case, the joint confidence regions are only conservative. Computational aspects and the practical implementation of the confidence regions are discussed and illustrated using an example.     

Development of supplier relationship including cost of defectives in the cyclic production

In the supply chain situation, a decision regarding supplier relationship is of high importance. This usually happens on the basis of supplier company parameters. In order to satisfy the demands, a buyer company often expects the supplier company to expedite their operations, i.e., to enhance the related production rate. In this context, presently the focus of this article is on the cyclic production environment at the supplier company premises. Any practical production process is expected to generate defective products also along with the normal usable products. After an estimation of this and the costs concerning defectives, it needs to be modelled in the cyclic manufacturing. This article incorporates specifically the cost of defectives along with the other relevant costs. After developing an interest in the inclusion of these costs, the supplier company is categorised. A contribution of this article is the development of supplier relationship in the discussed environment.     

“Crowding in” or “crowding out”? An examination of the impact of the welfare state on generalized social trust

Generalized social trust is correlated with increased levels of civic engagement, lower crime rates, and greater economic growth. Many scholars believe that equality provides the conditions in which social trust can flourish. Thus, welfare programs might be one way to generate social trust. However, the relationship between social spending and trust is contested: Some argue it is negative, while others argue it is positive. This study examined the effects of total social welfare expenditures on social trust in 18 OECD countries, holding constant individual characteristics, country characteristics, and country and year effects. Fixed effects analyses indicate that every additional percent of gross domestic product spent on social expenditures 5 years prior is associated with a 4.7 percent increased likelihood that respondents of that country will endorse trusting other people. Further testing for reverse causality found no significant association between trust and later social expenditures, supporting the claim that expenditures drive trust instead of the reverse.     

Measurement Equivalence Using Generalizability Theory: An Examination of Manufacturing Flexibility Dimensions

As the field of decision sciences in general and operations management in particular has matured from theory building to theory testing over the past two decades, it has witnessed an explosion in empirical research. Much of this work is anchored in survey‐based methodologies in which data are collected from the field in the form of scale items that are then analyzed to measure latent unobservable constructs. It is important to assess the invariance of scales across groups in order to reach valid, scientifically sound conclusions. Because studies have often been conducted in the field of decision sciences with small sample sizes, it further exacerbates the problem of reaching incorrect conclusions. Generalizability theory can more effectively test for measurement equivalence in the presence of small sample sizes than the confirmatory factor analysis (CFA) tests that have been conventionally used for assessing measurement equivalency across groups. Consequently, we introduce and explain the generalizability theory (G‐theory) in this article to examine measurement equivalence of 24 manufacturing flexibility dimension scales that have been published in prior literature and also compare and contrast G‐theory with CFA. We show that all the manufacturing flexibility scales tested in this study were invariant across the three industry SIC groups from which data were collected. We strongly recommend that G‐theory should always be used for determining measurement equivalence in empirical survey‐based studies. In addition, because using G‐theory alone does not always reveal the complete picture, CFA techniques for establishing measurement equivalence should also be invoked when sample sizes are large enough to do so. Implications of G‐theory for practice and its future use in operations management and decision sciences research are also presented.     

The impact of autonomy on information systems planning effectiveness

Autonomy for information systems planning may have an impact on the effectiveness of that planning. Theory Y suggests that when managers have more autonomy, they have greater feelings of ownership, commitment, and responsibility, and thus perform better. A postal survey of 131 chief information officers of US subsidiaries of multinational firms collected data to test hypotheses based on the theory. Data analysis revealed that autonomy for IS planning in general and the strategy selection planning activity in particular significantly predicted IS planning effectiveness. These findings thus extend the theory to a new domain, namely IS planning in multinational firms, and thereby facilitate a better understanding of the management of IS planning. They further suggest that parent managers consider delegating greater autonomy to the managers of their foreign subsidiaries.     

Simultaneous estimation of ordered parameters

The problem of estimating ordered parameters is encountered in biological, agricultural, reliability and various other experiments. Consider two populations with densities f₁(x₁-ω₁) and f₂(x₂-ω₂) where ω₁#ω₂. The estimation of ω₁,ω₂) with the loss function, the sum of squared errors, is studied. when f_i is the f_i(,_i,,_i ²) density with ,_i known, i=1,2; we obtain a class of minimax estimators. When ω₁ #ω₂ we show some of these estimators are improved by the maximum likelihood estimator. For a general f_i we give sufficient conditions for the minimaxity of the analogue of the Pitman estimator.     

A note on circular neighbor balanced designs

ABSTRACT

This paper describes some methods of constructing circular neighbor balanced and circular partially neighbor balanced block designs for estimation of direct and neighbor effects of the treatments. A class of circular neighbor balanced block designs with unequal block sizes is also proposed.