Adaptive Inference In Heteroskedastic Fractional Time Series Models

Giuseppe Cavaliere, Morten Nielsen and Robert Taylor

No 1390, Working Paper from Economics Department, Queen's University

Abstract: We consider estimation and inference in fractionally integrated time series models driven by shocks which can display conditional and unconditional heteroskedasticity of unknown form. Although the standard conditional sum-of-squares (CSS) estimator remains consistent and asymptotically normal in such cases, unconditional heteroskedasticity inflates its variance matrix by a scalar quantity, lambda>1, thereby inducing a loss in efficiency relative to the unconditionally homoskedastic case, lambda=1. We propose an adaptive version of the CSS estimator, based on non-parametric kernel-based estimation of the unconditional variance process. This eliminates the factor lambda from the variance matrix, thereby delivering the same asymptotic efficiency as that attained by the standard CSS estimator in the unconditionally homoskedastic case and, hence, asymptotic efficiency under Gaussianity. The asymptotic variance matrices of both the standard and adaptive CSS estimators depend on any conditional heteroskedasticity and/or weak parametric autocorrelation present in the shocks. Consequently, asymptotically pivotal inference can be achieved through the development of confidence regions or hypothesis tests using either heteroskedasticity robust standard errors and/or a wild bootstrap. Monte Carlo simulations and empirical applications are included to illustrate the practical usefulness of the methods proposed.

Keywords: adaptive estimation; conditional sum-of-squares; fractional integration; heteroskedasticity; quasi-maximum likelihood estimation; wild bootstrap (search for similar items in EconPapers)
JEL-codes: C12 C13 C22 (search for similar items in EconPapers)
Pages: 82 pages
Date: 2019-08
New Economics Papers: this item is included in nep-cta, nep-ecm and nep-ets
References: Add references at CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.econ.queensu.ca/sites/econ.queensu.ca/files/wpaper/qed_wp_1390.pdf First version 2019 (application/pdf)

Related works:
Journal Article: Adaptive Inference in Heteroscedastic Fractional Time Series Models (2022)
Working Paper: Adaptive Inference in Heteroskedastic Fractional Time Series Models (2020)
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:qed:wpaper:1390

Access Statistics for this paper

More papers in Working Paper from Economics Department, Queen's University Contact information at EDIRC.
Bibliographic data for series maintained by Mark Babcock ().