Naïvely testing for accruals mispricing in 26 equity markets -- one market at a time -- we find statistical evidence of anomalous returns in some countries. However, some of these findings might well be spurious because of data snooping biases that arise when simultaneously testing several...

This paper gives an unbiased estimator of the variance of overlapping returns. The estimator improves upon that proposed in Lo and MacKinlay (1988) [LM] (which is widely used in practice), as the LM estimator is consistent but not unbiased in small samples. The relevance of unbiasedness for...