Pricing the Currency Premium Under Flexible Exchange Rates

The currency premium is one of the three components of the differential between local and foreign interest rates. Emerging economies such as South Africa typically face positive interest rate differentials, that is, a higher cost of capital than developed economies. In this chapter we aim at identifying the determinants of the South African rand–U.S. dollar currency premium using monthly data over the period 1997–2008. We carry out an empirical analysis using dynamic time series econometric techniques to estimate the determinants of the one-month and one-year currency premia. Our findings show that the currency premia at both horizons are driven by long-run movements in the expected inflation differential between South Africa and the United States, risk aversion as a proxy for the price of rand exchange risk, and the volatility of the rand exchange rate as an indicator of the quantity of that risk. Misalignments in the real effective or rand–U.S. dollar bilateral exchange rates display mixed results in terms of their impact and statistical significance on both currency premium. Our parameter estimators overall are stable and robust to sample variations. Monetary policy is an important determinant of currency premia at both one-month and one-year horizons, but risk aversion is equally important to determine its time fluctuations.