Monthly data on the $US/ECU exchange rate are analysed in light of the random walk hypothesis. A battery of tests, including procedures that are robust to conditional heteroscedasticity, are applied against linear alternatives to departures from the random walk. These tests are all based on the...

The ability of futures markets to predict subsequent spot prices has been a controversial topic for a number of years. Empirical evidence to date is mixed; for any given market, some studies find evidence of efficiency, others of inefficiency. In part, these apparently conflicting findings reflect...

Recently developed methodology to allow the possibility of a stochastic unit root process as an alternative to a fixed parameter unit root model is applied to six national indices of stock market prices. Evidence supporting the stochastic unit root hypothesis is found. However, the...

This paper investigates the claim that the common finding of cointegration between spot and lagged forward exchange rates reflects the existence of covered interest arbitrage and not, as is generally accepted, long-run market efficiency. Breuer and Wohar's (1996) methodology is employed to match...

This study considers the possibility of estimating a Dickey-Fuller regression, constraining the autoregressive parameter to be at most one, and imposing prior knowledge of the sign of the drift parameter. In spite of apparently encouraging asymptotic results, it emerges that no feasible test of...

Unit root tests, seeking mean or trend reversion, are frequently applied to panel data. We show that more powerful variants of commonly applied tests are readily available. Moreover, power gains persist when the modifications are applied to bootstrap procedures that may be employed when...