Joint Variance-Ratio Tests of the Martingale Hypothesis for Exchange Rates
汇率鞅假设的联合方差比检验
There is considerable interest as to whether exchange races behave like martingales. Liu and He (1991) test the martingale hypothesis for exchange rates using the variance ratio methodology of Lo and MacKinlay (1988). They find that exchange rates have violated martingale property since the inception of floating rates in 1973. However, Liu and He did not consider the joint implications of their tests, In this paper, we reassess the martingale hypothesis for exchange rates…