Abstract
This article analyses multiple cyclical structures in financial time series. In particular, we focus on the monthly structure of the Nasdaq, the Dow–Jones and the S&P stock market indices. The three series are modelled as long-memory processes with poles in the spectrum at multiple frequencies, including the long-run or zero frequency.
Acknowledgement
Luis A. Gil-Alana gratefully acknowledges financial support from the Ministerio de Ciencia y Tecnologia (ECO2008-03035 ECON Y FINANZAS, Spain).
Notes
1Lobato and Robinson (Citation1998) proposed a semiparametric approach for testing this type of model, and Dalla and Hidalgo (Citation2005) suggested a parametric test where the unbounded frequency in the spectrum is assumed to be unknown.
2Note that, if j 1 = 1, then (1 − 2cos w j 1 L + L 2) d 1 = (1 − 2L + L 2) d 1 = (1 − L)2d 1 .
3Note that Robinson's (Citation1994) method is based on the Whittle function, which is an approximation of the likelihood function.