Uniform consistency of nonstationary kernel-weighted sample covariances for nonparametric regression
Publication Type
Journal Article
Version
publishedVersion
Publication Date
6-2016
Abstract
We obtain uniform consistency results for kernel-weighted sample covariances in a nonstationary multiple regression framework that allows for both fixed design and random design coefficient variation. In the fixed design case these nonparametric sample covariances have different uniform asymptotic rates depending on direction, a result that differs fundamentally from the random design and stationary cases. The uniform asymptotic rates derived exceed the corresponding rates in the stationary case and confirm the existence of uniform super-consistency. The modelling framework and convergence rates allow for endogeneity and thus broaden the practical econometric import of these results. As a specific application, we establish uniform consistency of nonparametric kernel estimators of the coefficient functions in nonlinear cointegration models with time varying coefficients or functional coefficients, and provide sharp convergence rates. For the fixed design models, in particular, there are two uniform convergence rates that apply in two different directions, both rates exceeding the usual rate in the stationary case.
Keywords
Cointegration, Functional coefficients, Kernel degeneracy, Nonparametric kernel smoothing, Random coordinate rotation, Super-consistency, Uniform convergence rates, Time varying coefficients
Discipline
Growth and Development
Research Areas
Econometrics
Publication
Econometric Theory
Volume
32
Issue
3
First Page
655
Last Page
685
ISSN
0266-4666
Identifier
10.1017/S0266466615000109
Publisher
Cambridge University Press
Citation
LI, Degui; Peter C. B. PHILLIPS; and GAO, Jiti.
Uniform consistency of nonstationary kernel-weighted sample covariances for nonparametric regression. (2016). Econometric Theory. 32, (3), 655-685.
Available at: https://ink.library.smu.edu.sg/soe_research/1944
Copyright Owner and License
Authors
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Additional URL
https://doi.org/10.1017/S0266466615000109