Open Access Short Communication

A Note on Estimating Unreported Sample Statistics for Meta-Analysis

Joseph G. Eisenhauer

Asian Journal of Probability and Statistics, Page 12-20
DOI: 10.9734/ajpas/2021/v13i130298

A major challenge confronting meta-analysts seeking to synthesize existing empirical research on a given topic is the frequent failure of primary studies to fully report their sample statistics.  Because such research cannot be included in a meta-analysis unless the unreported statistics can somehow be recovered, a number of methods have been devised to estimate the sample mean and standard deviation from other quantities.  This note compares several recently proposed sets of estimators that rely on extrema and/or quartiles to estimate unreported statistics for any given sample.  The simplest method relies on an underlying model of normality, while the more complex methods are explicitly designed to accommodate non-normality.  Our empirical comparison uses a previously developed data set containing 58 samples, ranging in size from 48 to 2,528 observations, from a standard depression screening instrument, the nine-item Patient Health Questionnaire (PHQ-9).  When only the median and extrema are known, we find that the estimation method based on normality yields the most accurate estimates of both the mean and standard deviation, despite the existence of asymmetry throughout the data set; and when other information is given, the normality-based estimators have accuracy comparable to that of the other estimators reviewed here.  Additionally, if the sample size is unknown, the method based on normality is the only feasible approach.  The simplicity of the normality-based approach provides an added convenience for practitioners. 

Open Access Policy Article

Employability Factors Contributing to Youth Unemployment in the EAC Countries Data and Policy Analysis

Semboja Haji Hatibu, Hafidh Ali Hafidh

Asian Journal of Probability and Statistics, Page 34-51
DOI: 10.9734/ajpas/2021/v13i130299

This policy research paper analyses employability factors and challenges contributing to youth unemployment and also provides working recommendations for further dialogue and engagement on youth employability in the East African community EAC Countries. The policy analysis is based on the theory of 4-Es as propounded by International Labour Organization ILO and Youth Employment Network literature. The field research survey, focus group discussion, combined observational and consultations with key informants were major research methods used in collecting secondary and primary data and information. Data analysis uses non-parametric methods, mainly frequency and cross tabulations.

The paper found that costs of doing business among the youth in the formal and informal economies are significantly high. There are weak limited skills matching systems and provision of relevant curriculum that produce an updated knowledge base. The problem of rural-urban migration is related to inadequate rural infrastructures; lack of establishment of sustainable agro-processing industries, limited provision of rural vocation and training programmes to equip youth with skills for employability. The education and training systems do not comply with regional, international standards and technological changes in the world. There are weak career counselling and guidance centres for youth. There is a limited access to good quality education and thus decent jobs for youth with disability.

The policy solution is to enhance employability conditions. Relevant policy strategies include reducing cost of doing business, enhance business skills development and matching; minimizing rural-urban migration; creating conducive environment for business for youth with disability; increasing agricultural mechanization to enhance productivity, increasing rural connectivity and accessibility; improving VET and higher education learning systems; increasing access to schools, technical and vocational training for youth with disability; improving conditions and quality of employment systems and enhancing provision of information regarding employment opportunities in these EAC countries.

Open Access Original Research Article

Wiener Index of Some Operations on Fuzzy Graphs

Saqr H. Al-Emrany, Mahiuob M. Q. Shubatah, Abdullah Q. Al-Mekhlafi

Asian Journal of Probability and Statistics, Page 1-11
DOI: 10.9734/ajpas/2021/v13i130296

In this paper, the concept of the Wiener index in some operations on fuzzy graphs was introduced and investigated. The bound of W(G) of some operations on fuzzy graphs are obtained like union, join, Cartesian product, composition, complete fuzzy graph, and bipartite complete fuzzy graph.

Open Access Original Research Article

Modeling Infant Mortality Risk Factors using Logistic Regression Model and Spatial Analysis in Kenya

Erick Cheruiyot Kirui, Elphas Luchemo, Ayubu Anapapa

Asian Journal of Probability and Statistics, Page 21-33
DOI: 10.9734/ajpas/2021/v13i130297

Globally, infant mortality is used as an important indicator for healthcare status hence an important tool for evaluation and planning of public health strategies. Despite of numerous interventions by governments aimed at reducing infant mortality, high rates are still reported in Kenya. A lot of resources are channeled towards its control leading to low productivity hence impacting the household economic welfare and national GD. The specific objective was to establish risk factors and the spatial variation of infant mortality in Kenya by analyzing the 2014 Kenya Demographic Health Survey data. A fully Bayesian paradigm and logistic regression model were used to determine infant mortality risk factors and spatial variation in Kenya. Demographic, socioeconomic and environmental factors were found to have significant effect on infant mortality. Counties from the northern parts of Kenya, Rift Valley, Central, Eastern, Nyanza, Coastal and Western parts of Kenya showed a high level of infant deaths. Infant mortality is high in arid and semi-arid areas and coastal areas due to high prevalence of infectious diseases and inadequate water supply, health facilities and low education levels. Infant mortality varies significantly across regions in Kenya due to cultural activities, and weather patterns hence exists spatial autocorrelation among neighboring regions.

Open Access Original Research Article

Linear and Non-Linear Modelling of Nigerian Crude Oil Prices

Wiri Leneenadogo, Sibeate Pius U

Asian Journal of Probability and Statistics, Page 52-63
DOI: 10.9734/ajpas/2021/v13i130300

To model Nigeria crude oil prices, this analysis compared univariate linear models to univariate nonlinear models. The data for this analysis was gathered from the Central Bank of Nigeria (CBN) Monthly Statistical Bulletin. The upward and downward movement in the series revealed by the time plot suggests that the series exhibit a regime-switching pattern: the cycle of expansion and contraction. At lag one, the Augmented Dickey-Fuller test was used to test for stationarity. For univariate linear ARIMA (p, d, q)) and univariate non-linear MS-AR, seven models were estimated for the linear model and two for the non-linear model. The best model was chosen based on the criterion of least information criterion,  AIC (2.006612), SC (2.156581), and the maximum log-likelihood of   (-150.5480) for the crude oil prices were used to pick MS-AR (1) for the series. In analysing crude oil prices data, the MS-AR model proposed by Hamilton outperforms the linear autoregressive models proposed by Box- Jenkins. The model was used to predict the series' values over a one-year cycle (12 months).