How predictable are precious metal returns?
研究了1987年至2014年间三种贵金属收益的可预测性随时间变化的情况，发现铂金可预测性最强、白银最弱，对投资者调整贵金属投资组合有参考价值。
This paper provides strong evidence of time-varying return predictability of three precious metals from January 1987 to September 2014. We use three variations of the variance ratio test, the nonlinear Brock, Dechert and Schieinkman test as well as the Hurst exponent to evaluate the time-varying return predictability of precious metals to reduce the risk of spurious results. Our full sample results report mixed findings where some tests indicate significant predictability while some suggest no predictability. However through a time-varying procedure, we show that each precious metal market goes through periods of significant predictability as well as periods of unpredictability. Therefore this finding suggests that return predictability does vary over time and is not a static, all-or-nothing condition and therefore is consistent with the adaptive market hypothesis. We also show that platinum is the most predictable of the three precious metals and silver the least predictable, which may be of great to investors who include precious metals in their investment portfolios.