The impact of macroeconomic variables on the equity market risk premium in South Africa

Abstract

The relationship between the Equity Market Risk Premium (MRP) and macroeconomic variables has been a subject of extensive discussion in the finance literature. The MRP is a central component of the main asset pricing models which are used to estimate the cost of equity which is mainly used in investment appraisal, performance measurement and valuation of equity assets. Past studies have identified inflation rate, interest rate, foreign exchange rate and political risk as the key macroeconomic variables that determine the size of the MRP. The test of the impact of these variables on the MRP have however been based mainly on data from developed countries and a few emerging countries. To the researcher’s knowledge, there are no studies that have investigated the impact of these macroeconomic variables on the MRP in South Africa. It is necessary to test the impact of these variables in the context of South Africa as these variables vary across countries. Using time series secondary data that was obtained from the SARB database, JSE database and World Bank database for the period 2002 to 2017, this study investigated the impact of these variables on the MRP in South Africa. A total of 192 observations per series of the inflation rate, interest rate, foreign exchange rate, political risk, JSE-ALSI and 91-days Treasury bill was used in the study. The data used were tested for possible misspecification errors that could arise from using a time series secondary data and the regression model was fitted using the Ordinary Least Square (OLS) estimator. The misspecification tests and models were both implemented on STATA 15 software. The results shows that inflation rate, interest rate and foreign exchange rate have a negative impact on the MRP whilst political risk has a positive impact on the MRP. Furthermore, the result shows that the inflation rate is the only variable amongst other variable tested that has a significant influence on the MRP for the study period. The study, therefore, concludes that inflation rate has the highest impact on the MRP in the context of South Africa. The study recommends that inflation rate should be monitored and kept within its target of 3-6% amongst other variables tested in order to increase investors’ confidence in the security market and also foster economic growth. The main limitations to the study were the limited data sources and insufficient funds.