“…Recently, there has been empirical evidence (for example, van Dijk and Franses (2000), Sarno (2000), Baum et al (2001), Kapetanios et al (2003), Liew et al (2003), Shively (2005), Baharumshah and Liew (2006), and Baillie and Kilic (2006)) that shows that financial time series are mostly nonlinear in nature. To cater for nonlinearity, Kapetanios et al (2003) propose to first estimate the following nonlinear autoregressive process: …”