Prediction of risks of sequence of events using multistage proportional hazards model: a marginal-conditional modelling approach

Statistical Methods & Applications - In many studies, sequence of events may occur over time that produce repeated measures with censored observations. Multi-state models are commonly used, and...     

Multiple linear regression model with stochastic design variables

In a simple multiple linear regression model, the design variables have traditionally been assumed to be non-stochastic. In numerous real-life situations, however, they are stochastic and non-normal. Estimators of parameters applicable to such situations are developed. It is shown that these estimators are efficient and robust. A real-life example is given.     

The substitutability of labor between immigrants and natives in the Canadian labor market: circa 1995

This paper examines the substitutability or complementarity between Canadian-born and immigrant workers. These are examined by estimating a set of wage equations using a generalized Leontief production function. The paper finds that, in general, there is no displacement of Canadian-born workers by immigrants. Recent immigrants affect the native-born positively, while older immigrants are neither substitute nor complement for natives. However, the effects differ across industries. Overall, the evidence that immigrants harm the opportunities of native-born workers is scant.

Multidimensional Human Opportunity Index

One fact that emerges from the evaluation of the Millennium Development Goals is that not all countries met all the goals and there are significant complementaries among failing on specific goals. This paper proposes the Multidimensional Human Opportunity Index (MHOI) that focuses on the complementaries among access to multiple services. We focus on access to services for children, with the aim of capturing equality in opportunity for children from diverse socio-economic backgrounds. This index builds on the Human Opportunity Index of the World Bank that measures children’s access to a basic service, such as access to clean water. However, the MHOI differs from the parent index in that we measure joint access to multiple services or access to a bundle of services. We apply the MHOI on two Himalayan states of South Asia, Nepal and Bhutan, and show that although each basic service is available to a large proportion of the population, only two-thirds in Bhutan and one half in Nepal have access to the bundle of basic services in 2011–2012.     

Estimation and hypothesis testing in multivariate linear regression models under non normality

This paper discusses the problem of statistical inference in multivariate linear regression models when the errors involved are non normally distributed. We consider multivariate t-distribution, a fat-tailed distribution, for the errors as alternative to normal distribution. Such non normality is commonly observed in working with many data sets, e.g., financial data that are usually having excess kurtosis. This distribution has a number of applications in many other areas of research as well. We use modified maximum likelihood estimation method that provides the estimator, called modified maximum likelihood estimator (MMLE), in closed form. These estimators are shown to be unbiased, efficient, and robust as compared to the widely used least square estimators (LSEs). Also, the tests based upon MMLEs are found to be more powerful than the similar tests based upon LSEs.     

Failure of Muslim Leadership in America From the Perspective of First-Generation Muslim Americans: A Phenomenological Study

While leadership is a foundational component of guidance in most societies, Muslim children born in America to immigrant parents lack such guidance. A qualitative case study was recently conducted with six first-generation Muslim American college students and professionals. The purpose of this study was six-fold: to examine the concept of leadership in Muslim communities in America, to observe perceptions of Muslim leadership in mosques and community centers, to examine the practice and beliefs of Muslims in America, to view the social interaction of Muslim Americans within their community, to view the mentorship and leadership aspects of Muslim Americans in their community and to inspect marital and cultural aspects within those societies. Findings reveal four themes that show that Muslim Americans are subject to role confusion as they go through adolescence and need a leadership role model to assist them through this stage.     

Household empowerment as the key to eradicate poverty incidence

The current study aimed to investigate how the household empowerment can potentially reduce the rural poverty incidence. The data were collected through multistage random sampling from the rural households of 24 villages in Southern Punjab, Pakistan. A total of 600 households were selected as sample pool. Face‐to‐face interviews with the household heads were conducted. The household empowerment was measured through an index that was adopted from Abrar‐ul‐haq (“An assessment of the role of household empowerment in alleviating poverty in Southern Punjab, Pakistan” (Ph.D. Dissertation), School of Economics, Finance and Banking, Universiti Utara Malaysia, 2017). The binary logit model was used to analyze the impact of household empowerment with other control variables on poverty incidence. The results of the current study confirm the negative nexus between household empowerment and poverty incidence of rural households as the study reported that the probabilities (odds ratio: 0.877) of being poor are reduced by increasing the empowerment (in every aspect, economically, politically, and socially) of the households, and the results are statistically significant at the 1% level of significance. Based on empirical results, this study suggests that household empowerment has significant potential to reduce poverty incidence in the rural areas of Southern Punjab, Pakistan.     

Tweeting Toward Transformation: Prison Abolition and Criminal Justice Reform in 140 Characters

The United States is the world leader in confining bodies behind bars. As scholars, practitioners, and activists struggle against the problem of mass incarceration, this article makes a distinction between two competing perspectives, both of which seek to change the current criminal legal system: “prison abolition” and “reformism.” Each represents ideological and political differences in how mass incarceration should and could be resolved. Prior research has relied on historical methods and data to examine theoretical departures between prison reform and prison abolition, yet to our knowledge, there have been no explorations of these perspectives on new media. This article fills the gap, drawing on a sample of 2,112,206 tweets between 2011 and 2020 and engaging in an in-depth qualitative analysis of nearly 5,000 tweets over a 6-year period in order to investigate the ways Twitter users disclose and define their positions on criminal justice reform on one hand, and prison abolition on the other, and how these discussions have changed over time.     

A guide to the design and analysis of small clinical studies

Clinical studies, which have a small number of patients, are conducted by pharmaceutical companies and research institutions. Examples of constraints that lead to a small clinical study include a single investigative site with a highly specialized expertise or equipment, rare diseases, and limited time and budget. We consider the following topics, which we believe will be helpful for the investigator and statistician working together on the design and analysis of small clinical studies: definitions of various types of small studies (exploratory, pilot, proof of concept); bias and ways to mitigate the bias; commonly used study designs for randomized and nonrandomized studies, and some less commonly used designs; potential ethical issues associated with small underpowered clinical studies; sample size for small studies; statistical analysis methods for different types of variables and multiplicity issues. We conclude the paper with recommendations made by an Institute of Medicine committee, which was asked to assess the current methodologies and appropriate situations for conducting small clinical studies.