Estimation of Parameters of Linear Econometric Model and the Power of Test in the Presence of Heteroscedasticity Using Monte-Carlo Approach

This paper is concerned with the estimation of parameters of linear econometric model and the power of test in the presence of heteroscedasticity using Monte-Carlo approach. The Monte Carlo approach was used for the study in which random samples of sizes 20, 50 and 100, each replicated 50 times were generated. Since the linear econometric model was considered, a fixed X variable for the different sample sizes was generated to follow a uniform distribution while 50 replicates of the stochastic error term for different sample sizes followed a normal distribution. Two functional form of heteroscedasticity  were introduced into the econometric model with the aim of studying the behaviour of the parameters to be estimated. 50 replicates of the dependent variable for each sample size was generated from the model  where the parameters,  were assumes to be 0.5 and 2.0 respectively. The Ordinary Least Squares (OLS) and the Generalized Least Squares (GLS) estimators were studied to identify which is more efficient in the presence of the two functional forms of heteroscedasticity considered. Both estimators were unbiased and consistent but none was convincingly more efficient than the other. The power of test was used to examine which test of heteroscedasticity (i.e., Glejser, Breusch-Pagan and White) is most efficient in the detection of any of the two forms of heteroscedasticity using different sample sizes. Glejser test detects heteroscedasticity more efficiently even in small sample sizes while White test is not as efficient when sample size is small compared to when the sample size is large.   Keywords: Heteroscedasticity, Monte Carlo, Power of Test, Ordinary Least Squares Estimator, Generalized Least Squares Estimator, Breusch-Pagan test, Glejser test, White test, Bias, Variance, Root Mean Square Erro

Inflationary Trend in Basic Amenities in Ibadan Oyo State, Nigeria using Price Indices

Trend of inflation was studied using price indices gotten from market survey conducted on the prices of food, clothes and building materials collected from major  markets in Ibadan, Oyo state, Nigeria in 2004 and 2014, 2004 being the base year. The price indices used were Laspeyres’, Paache’s, Fisher’s Ideal (FI) and Dorbey’s and Bowley’s (DB) with emphasis on Fisher’s and DB because of their advantages over others. A well-structured questionnaire was used to collect data on prices of food, clothes and building materials in these markets in 2004 and 2014. The results showed an increase between 40.27 and 460.26% increase in the prices of food items; an increase between 13.93 and 84.04% in the price of food items (provisions) except custard with a reduction of 15%; an increase between 11.2 and 100% in prices of cloths except ankara with less than 8% reduction in price and an increase between 5.9 and 69.7% in the price of building materials. Since price change affects planning, especially when citizen are face with stable income, efforts must be made by relevant authorities to control and stabilize the prices of these commodities. Keywords: Inflation, Basic amenities, Market survey, Price indices, Ibada

DOES MACRO ECONOMIC VARIABLES HAVE EFFECT ON STOCK MARKET MOVEMENT IN NIGERIA?

Over the past decades, numerous studies have analyzed the relationship and the different results obtained from these studies have motivated further research. The relationship between Average share price and macro – economic variable has been well documented for the developed markets. However, this paper seeks to address the question of whether macro – economic variables have a significant with stock market movement using time series annual data for the period from 1985 – 2008. The selected macro – economic variables for study include external debt, inflation rate, real interest rate, investment, and exchange rate. The research entails the use of Argumented Dickey Fuller test, multivariate cointegration test, vector error correction, variance decomposition and causality analysis. The result was that all the variables were stationary at 2nd difference, four cointegrating equations were present i.e. long run relationship exists between the selected macro –economic variable and average share price. All macro – economic variables were insignificant but all negative relationship with ASP but only External debt was significant related to ASP. ASP and External debt were found to granger cause in pairs while an independent causality exists between the selected macro – economic variable and ASP. These show that ASP is not a leading indicator for the selected macro – economic variable. Keywords: Macro-economic, Stock market, Inflation rate, multivariate cointegration test, External deb

FITTING THE STATISTICAL DISTRIBUTION FOR DAILY RAINFALL IN IBADAN, BASED ON CHI-SQUARE AND KOLMOGOROV- SMIRNOV GOODNESS-OF-FIT TESTS.

This paper presents several types of statistical distributions to describe rainfall distribution in Ibadan metropolis over a period of 30 years.The exponential, gamma, normal and poisson distributions are compared to identify the optimal model for daily rainfall amount based on data recorded at rain guage station at Forestry Research Institute of Nigeria, Jericho, Ibadan (FRIN). The models are evaluated based on chi- square and kolmogorov-smirnov tests. Overall, this study has shown that the exponential distribution is the best model followed by normal and poisson model that has the same estimated rainfall amount for describing the daily rainfall in Ibadan metropolis. Keywords: scale parameter, asymptotically, exponential distribution, gamma distribution, poisson and kolmogorov-smirnov

Effect of Multicolinearity and Autocorrelation on Predictive Ability of Some Estimators of Linear Regression Model

Violation of the assumptions of independent regressors and error terms in linear regression model has respectively resulted into the problems of multicollinearity and autocorrelation. Each of these problems separately has significant effect on parameters estimation of the model parameters and hence prediction.  This paper therefore attempts to investigate the joint effect of the existence of multicollinerity and autocorrlation on Ordinary Least Square (OLS) estimator, Cochrane-Orcutt (COR) estimator, Maximum Likelihood (ML) estimator and the estimators based on Principal Component (PC) analysis on prediction of linear regression model through Monte Carlo studies using the adjusted coefficient of determination goodness of fit statistic of each estimator. With correlated normal variables as regressors, it further identifies the best estimator for prediction at various levels of sample sizes (n), multicollinearity  and autocorrlation . Results reveal the pattern of performances of COR and ML at each level of multicollinearity over the levels of autocorrelation to be generally and evidently convex especially when  and while that of OLS and PC is generally concave. Moreover, the COR and ML estimators perform equivalently and better; and their performances become much better as multicollinearity increases. The COR estimator is generally the best estimator for prediction except at high level of multicollinearity and low levels of autocorrelation. At these instances, the PC estimator is either best or competes with the COR estimator. Moreover, when the sample size is small (n=10) and multicollinearity level is not high, the OLS estimator is best at low level of autocorrelation whereas the ML is best at moderate levels of autocorrelation. .Keywords: Prediction, Estimators, Linear Regression Model, Multicollinearity, Autocorrelation

Orange-fleshed Sweetpotato on the home grownschool feeding menu in Nigeria

Sweetpotato for health and wealth in Nigeria and Jumpstarting OFSP in West Africa for diversified markets are two projects that focus on development of the value chain for health and wealth of the rural households in Nigeria, working in Osun and Kwara states. Out of search for OFSP demand at the formal sector, inclusion in the school feeding menu was conceived. The flyer presents the stages of inception, advocacy and sensitization that resulted in the inclusion of OFSP in the School Feeding Program in Osun State, as well as the achievements made between June 2014 and July 2015, and plans for scaling up

Effects of Sodium Hydroxide Concentration on Zeolite Y Synthesized from Elefun Kaolinite Clay in Nigeria

Zeolite Y was synthesized hydrothermally from Elefun kaolinite clay. The raw kaolinite was calcined at 8500C to obtain more reactive clay (metakaolin). The metakaolin was dealuminated using non-heating methods to obtain the optimum dealumination route desired silica to alumina ratio between 3 and 7. The non-heating method proved successful in producing a desired ratio of 4 which was used in producing the aluminosilicate gel. The aluminosilicate gel was aged for 7 days at 950C for 36 hours with varying Na2O/SiO2 ratios of 0.60, 0.65, 0.70, 0.75 and 0.80 to produce zeolite Y. The synthesized zeolites were characterized by X-ray diffraction (XRD) analysis. The effect of NaOH concentration was studied using the XRD patterns of synthesized zeolite Y samples with reference to a standard zeolite Y. The results indicated zeolite Y of low crystallinity accompanied with other impure phases. Furthermore, the concentration of NaOH improved the intensity of the zeolite Y crystal peaks. The Na2O/SiO2 ratio that gave the highest crystallinity optimal ratio was found to be 0.75 with NaOH concentration of 3.8

Factors Influencing the Use of Information and Communication Technology in Real Estate Practice in Minna

The study explored motivating factors influencing the use of ICT in Minna.The target population were registered Estate Surveyors and Valuers domiciled and operating within the Minna property market. The respondents were extracted from the 2011 NIESV membership Directory.Survey data from 15 estate firms were collected to analyze the vital motivating factors influencing the use of ICT in real estate practice. A five point Likert scale was used to examine their opinions and spearman rank correlation was used to test if there is any relationship between internal and external motivating factors. The result indicated that increased productivity of staff, enhanced quality of customer services, knowledge sharing factor, information accessibility, improved decision making and time saving are the most influencing motivating factors while competitors' pressure, availability of ICT infrastructure, management and business size, reduced overall cost are less influencing motivating factors. The study further revealed that internal motivating factors strengthened the use of ICT in their domain. There is negative correlation between the internal and external motivating factors. Niger state branch of NIESV and ESVARBON should recommend the use of ICT to all estate firms and estate surveyors and valuers. Also, the work concludes by recommending further conduct of comprehensive indigenous research and development (R&D) in ICT driven real estate practice in Minna by liaison with various educational institutions offering estate management in their domain in order to be abreast of global best practices.Keywords: ICT, Real Estate Practice, Motivating Factors, Nigeri

Theoretical Issues and Conceptual Framework for Physical Facilities Design in Hospital Buildings

This study reviewed the theoretical issues relating to morphological and psychological design issues in hospital building design evaluation. The study of morphological configurations design issues, concentrates on the elements of building, shape/form, the structure of the environment, the structural efficiency and the architectural appearance of the hospital building forms. The psychological design issues focused on the essential issues relating to Proximity, Privacy and Wayfindings. Through the literature review of previous models such as, Khan (2012) Operational Efficiency Model, Haron, Hamid and Talib Usability Framework, (2012), Zhao, Mourshed & Wright (2009) Model, Alalouch, Aspinall & Smith Model (2016) and Hill & Kitchen (2009). A conceptual framework for physical facilities design evaluation and satisfaction in hospital buildings was developed. The study, however, provides useful information for the development of a design framework that can inform policy on hospital buildings