This paper analyses the constant elasticity of volatility (CEV) model suggested by [6]. The CEV model without mean …

volatility) associated with financial returns, was the portmanteau statistic for non-causality in variance of Cheng and Ng (1996 … the paper is to derive a simple test for causality in volatility that provides regularity conditions arising from the …

volatility) associated with financial returns was the portmanteau statistic for non-causality in the variance of Cheng and Ng … affect the power of the test. The purpose of the paper is to derive a simple test for causality in volatility that provides …

volatility models …