Mean reversion in Southeast Asian stock markets

This paper assesses the predictable component of South East Asian stock markets using a bootstrap resampling method to estimate the small sample distributions of variance ratio statistics. We find evidence of mean reversion in long horizon dollar adjusted excess returns. The robustness of the results is assessed by adjusting stock returns for potential time-varying expected returns and partial integration of these emerging markets into world capital markets. In all but one case, mean reversion is shown to be due to either time-variation of risk exposure and prices of risk or partial integration of the local market into world stock markets. These results clearly illustrate the dangers of testing market efficiency without carefully adjusting stock returns for time variation in expected returns and the partial integration of local markets into world markets.