Shrinkage estimation in lognormal regression model for censored data

We introduce in this paper, the shrinkage estimation method in the lognormal regression model for censored data involving many predictors, some of which may not have any influence on the response of interest. We develop the asymptotic properties of the shrinkage estimators (SEs) using the notion of asymptotic distributional biases and risks. We show that if the shrinkage dimension exceeds two, the asymptotic risk of the SEs is strictly less than the corresponding classical estimators. Furthermore, we study the penalty (LASSO and adaptive LASSO) estimation methods and compare their relative performance with the SEs. A simulation study for various combinations of the inactive predictors and censoring percentages shows that the SEs perform better than the penalty estimators in certain parts of the parameter space, especially when there are many inactive predictors in the model. It also shows that the shrinkage and penalty estimators outperform the classical estimators. A real-life data example using Worcester heart attack study is used to illustrate the performance of the suggested estimators.     

Maximum Likelihood Estimators in Regression Models for Error‐prone Group Testing Data

Since Dorfman's seminal work on the subject, group testing has been widely adopted in epidemiological studies. In Dorfman's context of detecting syphilis, group testing entails pooling blood samples and testing the pools, as opposed to testing individual samples. A negative pool indicates all individuals in the pool free of syphilis antigen, whereas a positive pool suggests one or more individuals carry the antigen. With covariate information collected, researchers have considered regression models that allow one to estimate covariate‐adjusted disease probability. We study maximum likelihood estimators of covariate effects in these regression models when the group testing response is prone to error. We show that, when compared with inference drawn from individual testing data, inference based on group testing data can be more resilient to response misclassification in terms of bias and efficiency. We provide valuable guidance on designing the group composition to alleviate adverse effects of misclassification on statistical inference.     

Formation and negotiation of identity: the case of the Kelantan Kampung Pasir Parit Peranakan Chinese

This article examines the formation and negotiation of identity among the Kampung Pasir Parit Peranakan Chinese, a unique sub-ethnic group of acculturated Chinese in Kelantan. Apart from their original Chinese identity, the Kampung Pasir Parit Peranakan Chinese have also adopted two additional identities, namely Malay and Siamese identities. Intermarriage with Siamese women in the early years is the main reason for the adoption of the Siamese identity, while regular social interactions with the local Malays have led to the adoption of a Malay identity. Thus, the identity of the Kampung Pasir Parit Peranakan Chinese comprises three contrasting components. Given such a complex identity, there is always a need for the Kampung Pasir Parit Peranakan Chinese to negotiate their identities to avoid any identity crisis. This negotiation of identity is at times demonstrated by the co-existence of identities and at times the clear demarcation of identities to fulfil different situational needs.     

Income Dependency on Non-timber Forest Products: An Empirical Evidence of the Indigenous People in Peninsular Malaysia

The indigenous people have been identified to be among the poorest and the most socioeconomically and culturally marginalized people all over the world. The main purpose of the paper is to explore the socioeconomic and demographic factors of indigenous people in Peninsular Malaysia in context of poverty and the role of income dependency of non-timber forest products (NTFP). The data were collected in 2014 and 2015 through primary and secondary sources. Partial least squares (PLS) method was used to analysis the data. PLS is a modeling technique that features multiple regression and principal component analysis. The study shows that still a large number of indigenous households is involved in the NTFP activities. But the communities are moving away from NTFP based income to cash-crop based income because of poor sustainable forest management and lack of forest property rights. However, NTFP have a significant role in the household income and contribute 24% of the average income. Moreover, the analysis shows that location is significant to the poverty. There should be a suitable sustainable forest management system which can teach these indigenous communities about proper way of NTFP gathering and given proper rights to forest land. Furthermore, education is not significant to indigenous people and there is a high rate of school dropout among them. The government should introduce a different education system for indigenous communities which will emphasize the importance of education to them.     

A Child Labour Estimator: A Case of Bahawalpur Division

Social Indicators Research - Child labor is a distressing issue. There have been many attempts to estimate its magnitude. It is attempted here to develop an estimator to assess the magnitude of...     

On the comparison of the pre-test and shrinkage estimators for the univariate normal mean

The estimation of the mean of an univariate normal population with unknown variance is considered when uncertain non-sample prior information is available. Alternative estimators are defined to incorporate both the sample as well as the non-sample information in the estimation process. Some of the important statistical properties of the restricted, preliminary test, and shrinkage estimators are investigated. The performances of the estimators are compared based on the criteria of unbiasedness and mean square error in order to search for a ‘best’ estimator. Both analytical and graphical methods are explored. There is no superior estimator that uniformly dominates the others. However, if the non-sample information regarding the value of the mean is close to its true value, the shrinkage estimator over performs the rest of the estimators. Received: June 19, 1999; revised version: March 23, 2000     

The production of space in the negotiation of water and electricity supply in a bosti of Dhaka

Dhaka Water Supply and Sewerage Authority (DWASA) and Dhaka Electricity Supply Company (DESCO) do not provide any direct utility supply in the informal settlements of Dhaka where more than one third of the total city population live. Large numbers of the population thus access utilities from local vendors who maintain relationships with administrative staff of the authorities concerned, political leaders and influential community leaders, thus making the supply available in the settlement and continuing their informal utility business. Access to these utilities is negotiated in the continuously changing arrangements of a complex hybrid institutional sphere and under informal regulation. In this process, the changing nature of the state and urban groups and the complicated and dynamic relationship between and within urban groups indicate that urban governance operates in a ‘third space’ of constant negotiation and contestation. Against this background this paper presents the informal practice of water and electricity supply by a local association, the regulations in place, and the inter-linkage between different forms of regulatory space whose presence is a necessary condition for the continuation of the informal practice.     

Framing inter-religious dispute: a comparative analysis of Chinese-, English-, and Malay-language newspapers in Peninsular Malaysia

Religious and ethnicity issues in multicultural societies have always been difficult to report. This study aims to conduct a framing analysis of the coverage of the biggest inter-religious dispute in Malaysia to date – the “Allah” dispute. Specifically, the study compares the coverage of Chinese-, English-, and Malay-language newspapers and assesses the factors that lead to differences in frame building. The findings showed that these newspapers reported the dispute with different degrees of intensity and prominence, and they employed different news sources. Although conflict appeared to be the salient frame used by the dailies, the aspects highlighted by them varied. Sin Chew (Chinese-language daily) was the most vocal in its coverage, which reflected a counter-hegemonic discourse. The Star (English-language daily) used a moderate approach, while Utusan (Malay-language daily) strongly supported the status quo. The frames built by The Star and Utusan could be attributed to the fact that these two newspapers were inclined to serve the politically vested interests of their owners.     

The impact of childhood mortality on Fertility in six rural Thanas of Bangladesh

In this article, we examine the relationship between child mortality and subsequent fertility using prospective longitudinal data on births and childhood deaths occurring to nearly 8000 Bangladeshi mothers observed over the 1982-1993 period, a time of rapid fertility decline. Generalized hazard-regression analyses are employed to assess the effect of infant and child mortality on the hazard of conception, with controls for birth order and maternal age and educational attainment. Results show that childhood mortality reduces the time to subsequent conception if the death occurs within a given interval, representing the combined effect of biological and volitional replacement. The time to conception is also reduced if a childhood death occurs during a prior birth interval, a finding that signifies an effect of volitional replacement of the child that died. Moreover, mortality effects in prior birth intervals are consistent with hypothesized insurance (or hoarding) effects. Interaction of replacement with elapsed time suggests that the volitional impact of child mortality increases as the demographic transition progresses. This volitional effect interacts with sex of index child. Investigation of higher-order interactions suggests that this gender-replacement effect has not changed over time.