This paper introduces a new method for estimating variance matrices. Starting from the orthogonal decomposition of the sample variance matrix, we exploit the fact that orthogonal matrices are never ill-conditioned and therefore focus on improving the estimation of the eigenvalues. We estimate...

This paper extends the classical local Whittle estimation procedure of the memory parameter to fractionally-integrated I(d) processes for d∈(-3/2,∞), covering stationary and nonstationary regions. We introduce the concepts of fully-extended discrete Fourier transform and periodogram. We...

This paper deals with the estimation of the long-run variance of a stationary sequence. We extend the usual Bartlett-kernel heteroskedasticity and autocorrelation consistent (HAC) estimator to deal with long memory and antipersistence. We then derive asymptotic expansions for this estimator and...