Simultaneous Inference on the Korean Won-US Dollar Forward Premium Anomaly

The forward premium anomaly, which refers to the empirical failure of the uncovered interest parity (UIP), has been primarily examined by the forward premium regression of [Fama, E. (1984). Forward and spot exchange rates. Journal of Monetary Economics, 14(3), 319–338. https://doi.org/10.1016/0304-3932(84)90046-1]. Some studies apply the rolling-window regression to capture the time-varying coefficient on the forward premium, with difficulty in statistically testing the deviation of the coefficient from the UIP over time. We follow [Baillie, R., & Kim, K. (2015). Was it risk? Or was it fundamentals? Explaining excess currency returns with kernel smoothed regressions. Journal of Empirical Finance, 34, 99–111] to apply the simultaneous inference procedure to the Korean Won-US Dollar spot and forward exchange rates by estimating the time-varying coefficient from the kernel-smoothed local-linear regression and constructing the uniform confidence band to test the local deviation. We find that, while the UIP is not rejected from the baseline regression, the simultaneous inference shows that the deviation from the UIP is mainly observed during the early 2000s and 2010s. Time-variation of the forward premium coefficient tends to be significantly affected by economic uncertainties such as the interest rate, inflation, and stock return volatilities in Korea and US.