On a class exhibiting trend change in average failure rate

Abstract

Weak convergence and moment convergence issues are investigated for the New Better than Average Failure Rate (NBAFR) family (introduced by Loh (1984 Loh, W. Y. 1984. A new generalization of the class of NBU distributions. IEEE Transactions on Reliability R-33 :97–113[Crossref], [Web of Science ®] , [Google Scholar])). We explore the validity of these results in the context of a more general ageing class that we introduce. We prove some new properties of this class and derive its interrelationships with other non-monotonic ageing families. Reliability and moment bounds are obtained and an interesting characterization of exponentiality is proved. Special cases of our results lead to new theorems for the NBAFR class. Finally weak convergence and related issues are established for this class.     

The status of women among the scheduled tribes in India

The scheduled tribes constitute about 8.2% of the total population in India. Although there is a large volume of anthropological literature describing the characteristics of and differences among the various tribes in India, little inter-disciplinary research has been done to uncover the status of women among the tribal population in India. This paper will analyze the status of women among the scheduled tribes in India. Frequent comparisons will be made to the social and cultural practices of the scheduled tribes, mainstream Hindus, as well as the scheduled caste population. Through this analysis, we will show the distinctiveness of the tribal cultures and the fact that many women from the scheduled tribes face less discrimination than Hindu women and those from scheduled castes.     

Long term demographic effect of a constant stream of immigration when the population is not reproducing itself

The author describes the use of a model to investigate "the age composition of the stationary population resulting from a condition of below replacement fertility and a continuous stream of immigrants, the size of which for any age remain invariant over time.... We have shown that the number dying among [migrants] is the same as the number of them entering over any time interval, and that is precisely how their stationarity is maintained." The geographical focus is on developed countries that are experiencing below-replacement fertility levels. (SUMMARY IN FRE AND SPA)     

Re-Defining the Who,When, and Where of Mentoring for Professional Statisticians

Organizations tailor their mentoring strategies to accommodate internal resources and preferences, producing different approaches in academic, government, and corporate environments. Across these settings, three common barriers impede effective mentoring of statisticians: overspecialization, time constraints, and geographic dispersion. The authors share mentoring strategies that have emerged at their organization, Mathematica Policy Research, to overcome these obstacles. Practices include creating a methodology working group to unite researchers with diverse backgrounds, integrating mentoring into existing workflows, and harnessing modern technological infrastructure to facilitate virtual mentoring. Although these strategies emerged within a specific professional context, they suggest opportunities for statisticians to expand the channels through which mentorship can occur.     

BERTRAND COMPETITION WITH ASYMMETRIC MARGINAL COSTS

This article tests the prediction of three discrete asymmetric duopoly price competition games in the laboratory. The games differ from each other in terms of the size of the cost asymmetry that induces a systematic variation in the difference between the firms' marginal costs. While the standard theory requires the low‐cost firm to set a price just equal to the high‐cost firm's marginal cost, which is identical across all three games, and win the entire market, intuition suggests that market price may increase with a decrease in the absolute difference between the two marginal costs. We develop a quantal response equilibrium model to test our competing conjecture. (JEL L11, L12, C91, D43)     

Measurement error in regression analysis

Consider the linear regression model Y = Xθ+ ε where Y denotes a vector of n observations on the dependent variable, X is a known matrix, θ is a vector of parameters to be estimated and e is a random vector of uncorrelated errors. If X'X is nearly singular, that is if the smallest characteristic root of X'X s small then a small perurbation in the elements of X, such as due to measurement errors, induces considerable variation in the least squares estimate of θ. In this paper we examine for the asymptotic case when n is large the effect of perturbation with regard to the bias and mean squared error of the estimate.     

Implementing a Multidimensional Poverty Measure Using Mixed Methods and a Participatory Framework

Recently, there have been advances in the development of multidimensional poverty measures. Work is needed however on how to implement such measures. This paper deals with the process of selecting dimensions and setting weights in multidimensional poverty measurement using qualitative and quantitative methods in a participatory framework. We estimate the multidimensional poverty measures developed by Alkire and Foster for a particular group: persons with psychiatric diagnoses in the United States. To select relevant dimensions and their relative ordering, two discussion groups are convened: one consisting of persons with lived-experience expertise and the other consisting of people with mental health service provision or research expertise. Several methods are used to convert dimension rankings into weights. The selection and ordering of dimensions differed between the two discussion groups, as did the resulting poverty measures. For instance, the poverty headcount using the dimensions and weights of the ‘lived experience’ group ranged from 20.61 to 26.96% as compared to a range of 18.62–33.19% using those of the ‘provider/researcher’ group. One of the main results of this study is that the Alkire Foster method is sensitive to the selection of dimensions and the methods used to derive rankings and weights. It points toward the limitation of relying exclusively on small scale qualitative methods for the selection and ranking of dimensions. In addition, the participatory framework used in this study was found to be essential in interpreting results, in particular with respect to the limitations of the data set in measuring relevant dimensions.     

Social Capital Investment and Immigrant Economic Trajectories: A Case Study of Punjabi American Taxi Drivers in New York City

Although the scholarship on social capital and immigrant economic incorporation has sufficiently documented how immigrants mobilize social capital in their search for employment which often leads to the formation of immigrant niches, how social capital is processed after immigrants acquire employment and its significance for the preservation of immigrant employment niches is less well explored. This paper addresses this gap in the literature with a case study of immigrant Punjabi taxi drivers in the New York metropolitan area. In particular, this study shows how a group of immigrant Punjabi taxi drivers mobilized social capital via embeddedness in co‐ethnic social networks and improved their working conditions – a process that must be considered in explanations of the Punjabi niche in the taxi industry for more than two decades. The study has implications for the relationship between social capital and the structure of the workplace or industry where immigrants are incorporated and its subsequent impact on immigrant economic trajectories. Further, this study contributes to the debate on the usefulness of ethnic communities for the adaptation of immigrant groups. Additionally, this research is relevant to the scholarship on the economic adaptation of South Asian (a subset of Asian Americans) immigrants, an understudied immigrant group in the United States.