Private Wage Returns to Schooling in Nigeria: 1996-1999

In the last two decades, primary and secondary school enrollment rates have declined in Nigeria while enrollment rates in post-secondary school have increased. This paper estimates from the General Household Survey for Nigeria the private returns to schooling associated with levels of educational attainment for wage and self-employed workers. The estimates for both men and women are small at primary and secondary levels, 2 to 4 percent, but are substantial at post-secondary education level, 10-15 percent. These schooling return estimates may account for the recent trends in enrollments. Thus, increasing public investment to encourage increased attendance in basic education is not justifiable on grounds of private efficiency, unless investments to increase school quality have higher private returns. With high private returns to post-secondary schooling, students at this level should pay tuition, to recoup more of the public costs of schooling, which may be redistributed to poor families through scholarships.Schooling Investment; Private Wage Returns; Efficiency; Equity; Nigeria

Analyzing Child Mortality in Nigeria with Geoadditive Survival Models

Child mortality reflects a country's level of socio-economic development and quality of life. In developing countries, mortality rates are not only influenced by socio-economic, demographic and health variables but they also vary considerably across regions and districts. In this paper, we analyze child mortality in Nigeria with flexible geoadditive survival models. This class of models allows to measure small-area district-specific spatial effects simultaneously with possibly nonlinear or time-varying effects of other factors. Inference is fully Bayesian and uses recent Markov chain Monte Carlo (MCMC) simulation. The application is based on the 1999 Nigeria Demographic and Health Survey. Our method assesses effects at a high level of temporal and spatial resolution not available with traditional parametric models

Geoadditive Latent Variable Modelling of Count Data on Multiple Sexual Partnering in Nigeria

The 2005 National HIV/AIDS and Reproductive Health Survey in Nigeria provides evidence that multiple sexual partnering increases the risk of contracting HIV and other sexually transmitted diseases. Therefore, partner reduction is one of the prevention strategies to accomplish the Millenium development goal of halting and reversing the spread of HIV/AIDS. In order to explore possible association between sexual partnering and some risk factors, this paper utilizes a novel Bayesian geoadditive latent variable model for count outcomes. This allows us to simultaneously analyze linear and nonlinear effects of covariates as well as spatial variations of one or more latent variables, such as attitude towards multiple partnering, which in turn directly influences the multivariate observable outcomes or indicators. Influence of demographic factors such as age, gender, locality, state of residence, educational attainment, etc., and knowledge about HIV/AIDS on attitude towards multiple partnering is also investigated. Results can provide insights to policy makers with the aim of reducing the spread of HIV and AIDS among the Nigerian populace through partner reduction

Geoadditive latent variable modelling of count data on multiple sexual partnering in Nigeria

The 2005 National HIV/AIDS and Reproductive Health Survey in Nigeria provides evidence that multiple sexual partnering increases the risk of contracting HIV and other sexually transmitted diseases. Therefore, partner reduction is one of the prevention strategies to accomplish the Millenium development goal of halting and reversing the spread of HIV/AIDS. In order to explore possible association between sexual partnering and some risk factors, this paper utilizes a novel Bayesian geoadditive latent variable model for count outcomes. This allows us to simultaneously analyze linear and nonlinear effects of covariates as well as spatial variations of one or more latent variables, such as attitude towards multiple partnering, which in turn directly influences the multivariate observable outcomes or indicators. Influence of demographic factors such as age, gender, locality, state of residence, educational attainment, etc., and knowledge about HIV/AIDS on attitude towards multiple partnering is also investigated. Results can provide insights to policy makers with the aim of reducing the spread of HIV and AIDS among the Nigerian populace through partner reduction.factor loading; geographical variations; latent variable model; MCMC; Nigeria; semiparametric Poisson model

Bayesian Geoadditive Seemingly Unrelated Regression

Parametric seemingly unrelated regression (SUR) models are a common tool for multivariate regression analysis when error variables are reasonably correlated, so that separate univariate analysis may result in inefficient estimates of covariate effects. A weakness of parametric models is that they require strong assumptions on the functional form of possibly nonlinear effects of metrical covariates. In this paper, we develop a Bayesian semiparametric SUR model, where the usual linear predictors are replaced by more flexible additive predictors allowing for simultaneous nonparametric estimation of such covariate effects and of spatial effects. The approach is based on appropriate smoothness priors which allow different forms and degrees of smoothness in a general framework. Inference is fully Bayesian and uses recent Markov chain Monte Carlo techniques

Analysis of Button Bit Wear and Performance of Down-The-Hole Hammer Drill

This work investigates bit button wear and performance of Down-The Hole Hammer (DTH) drill in Navachab Gold Mine, Namibia. Rock samples obtained were tested in the laboratory for chemical composition, equivalent quartz content and compressive strength. Schmidt hammer was used to determine the rebound hardness values of the selected rocks. The specific energy was determined by using empirical equation. The length of insert buttons on the surface of the drill bits were measured by using digital vernier caliper at regular intervals as drilling operation progressed and wear rates were correlated with the rock properties. Silica content varied from 71.34 – 71.83% and 83.25 – 83.56% for oxidised and non-oxidised schist respectively. The equivalent quartz content was estimated to 72.30% for oxidised schist and 64.20% for non-oxidised schist. The highest wear rate was experienced on the non-oxidised schist having equivalent quartz content of 72.30%. This revealed that wear of rock drill bit is influenced by rock properties. Uniaxial compressive strength varied from 123 to 194 MPa. The strength characteristics of these rocks varied from medium to high strength. Rebound hardness values from the LType schmidt hammer ranged from 42 to 58 for oxidised and non-oxidised schist. Rebound hardness values obtained from N-Type schmidt hammer varied from 50 to 58 for oxidised and non oxidised schist. The specific energy varied from 6.0 MJ/m3 for oxidised schist to 12.5 MJ/m3 for non-oxidised schist. Moreso, wear rate varied from 0.0284 - 0.1045 mm/m for oxidised and non oxidised schist respectively. The result of correlation matrix revealed that uniaxial compressive strength, equivalent quartz content and silica content are dominant rock properties affecting wear rate of bit button of DTH drill.Keywords: Wear, Button, Down-The-Hole, Drill, Performanc

Intra-Household Redistribution of Income and Calorie Consumption in South-Western Nigeria

This study investigates how per capita calorie intake in low income households of rural southwestern Nigeria responds to changes in total household income and women's share of household income. The study addresses two major questions. First, is calorie-income elasticity large enough to justify the use of income increases as a food/nutrition policy strategy for increasing calorie intake among low income households? Second, what is the potential effect of intra-household redistribution of income from men to women on per capita calorie consumption? My results show that calorie-income elasticity is small and close to zero, implying that income policies may not be the most effective way to achieve substantial improvements in calorie consumption. I also find that increases in women's share of household income are likely to result in marginal declines in per capita food calorie intake, suggesting that income redistribution from men to women would not increase per capita food energy intake in these households.Nigeria, Intra-Household Redistribution of Income, Women's Income Share Elasticity, Income Elasticity, Calorie Consumption.