Modelling and Forecasting Volatility of Returns on the Ghana Stock Exchange Using Garch Models

Abstract

In this paper the author examine the effect of imports, and exports on service sector productivity of Ghana for the period 1970-2013, using annual time series data. The Augmented Dickey-Fuller test (ADF), and the KwiatKowski (KPSS) test were used for the assessment of the effect of external shock on imports, exports, and service sector productivity whereas the ordinary least square method (OLS) was used to examine the role of import, and export on service sector productivity. The results indicate that the effect of external shock to imports, exports, and service sector productivity are permanent and not temporary. There is negative significant effect of export and positive effect of import on service sector productivity in Ghana during the period of discussion. The results suggest that policy makers can rely on import to influence service sector productivity and not export. Future studies should examine the effect of import of goods and services on the service sector productivity to determine whether the current findings will be replicated since the current study used export and import volumes.