Volume 5, Issue 1, 2017

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https://ir.unilag.edu.ng/handle/123456789/3814

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Browsing Volume 5, Issue 1, 2017 by Author "Akinyemi, M.I"

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  • Item
    Open Access
    Forecasting the Tail Density of Nigerian Exchange Rates with a Mixture, Autoregressive Model
    (University of Lagos Press, Akoka, 2017) Akinyemi, M.I; Boshnakov, G.N; Rufai, A
    Density forecasts have become more popular as real life scenarios require not only a forecast estimate but also the uncertainty associated with such a forecast. The class of mixture autoregressive (MAR) models provide a flexible way to model various features of financial time series and are also suitable for density forecasting. This study forecasted the out-of-sample tail density of Nigerian foreign exchange rates using MAR models with Student-t innovations. The model parameters were estimated using the maximum likelihood method. The forecast results of the MAR model were compared with some competing asymmetric Generalised Autoregressive Conditional Heteroskedastic (GARCH) models. Comparisons were based on the Berkowitz tail test. The test results suggested that the MAR model provided the best out-of-sample tail-density forecasts. The findings support the suggestion that the MAR models are well suited to capture the kind of data dynamics present in financial data and provide a useful alternative to other models.
  • Item
    Open Access
    Monitoring of Concentration of Air Pollutants from Vehicular Emission along Major Highways and Bypass within Kosofe Local Government Area, Lagos State
    (University of Lagos Press, Akoka, 2017) Oluseyi, T.O; Akinyemi, M.I
    Vehicular emissions are considered a major source of urban air pollution. Pollutants from these emissions whether as individual compounds or by synergistic interaction impacts negatively on public health, vegetation and climate. In this paper, we evaluate baseline concentration of carbon monoxide (CO), oxides of nitrogen (NOx), sulphur dioxide (SO2) and particulate matter (PM) from vehicular emissions during peak and off-peak periods along 3 major highways within Kosofe and Ikeja Local Government Areas (LGA) of Lagos State. Air quality monitoring/gas detection equipment were used to measure (in-situ method) ambient levels of the pollutant in nine locations within the selected area. The results revealed that the Federal Ministry of Environment’s Ambient Air Quality Standard limit was exceeded by most of the gases in majority of the locations. Statistical analysis revealed significant variations in the concentration of these gases across locations. Heavy vehicular traffic, poor traffic management and frequent traffic congestion were observed as factors responsible for the high pollutant concentration.