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...