Bekaert, Geert; Hodrick, Robert J; Zhang, Xiaoyan - C.E.P.R. Discussion Papers - 2010
We examine aggregate idiosyncratic volatility in 23 developed equity markets, measured using various methodologies, and we find no evidence of upward trends when we extend the sample till 2008. Instead, idiosyncratic volatility appears to be well described by a stationary autoregressive process...