16-11-2016 · From the field

Is the relationship between risk and return positive or negative?

This paper challenges the earlier work of Fu (2009). He claims to find a positive empirical relationship between risk and return using a sophisticated (EGARCH) idiosyncratic volatility measure for risk. Fu’s result flies directly in the face of the large number of studies that find strong evidence for a low-volatility anomaly.

Guo, Kassa and Ferguson resolve this inconsistency by showing that the findings of Fu (2009) can be fully explained by a serious flaw in his research methodology, namely look-ahead bias, i.e. the use of data that would not have been available during the period being analyzed. This example illustrates the importance of studies that attempt to validate the findings of others and of conducting out-of-sample tests, even for studies that have been published in top academic journals.

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