Discussion

Abstract

As already mentioned in a preceding chapter, controversial research results were obtained from the quantitative analysis across the observed periods. Whereas in the first period from 2003 until 2006 a statistically significant Granger causal relationship was detectable, it was not the case in the following years between 2007 and 2013. Unfortunately, the distinction between economic crisis and economic boom, that was considered when framing the time horizons of the analysed periods, does not provide an explanation for the unstable causality, because in such a case, the VIX would also have caused the SPX in the last periods.