Quantile-Wavelet Nonparametric Estimates for Time-Varying Coefficient Models

The paper considers quantile-wavelet estimation for time-varying coefficients by embedding a wavelet kernel into quantile regression. Our methodology is quite general in the sense that we do not require the unknown time-varying coefficients to be smooth curves of a common degree or the errors to be...

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Main Authors: Xingcai Zhou, Guang Yang, Yu Xiang
Format: Article
Language:English
Published: MDPI AG 2022-07-01
Series:Mathematics
Subjects:
Online Access:https://www.mdpi.com/2227-7390/10/13/2321
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author Xingcai Zhou
Guang Yang
Yu Xiang
author_facet Xingcai Zhou
Guang Yang
Yu Xiang
author_sort Xingcai Zhou
collection DOAJ
description The paper considers quantile-wavelet estimation for time-varying coefficients by embedding a wavelet kernel into quantile regression. Our methodology is quite general in the sense that we do not require the unknown time-varying coefficients to be smooth curves of a common degree or the errors to be independently distributed. Quantile-wavelet estimation is robust to outliers or heavy-tailed data. The model is a dynamic time-varying model of nonlinear time series. A strong Bahadur order <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>O</mi><mfenced separators="" open="{" close="}"><msup><mfenced separators="" open="(" close=")"><mfrac><msup><mn>2</mn><mi>m</mi></msup><mi>n</mi></mfrac></mfenced><mrow><mn>3</mn><mo>/</mo><mn>4</mn></mrow></msup><msup><mrow><mo>(</mo><mo form="prefix">log</mo><mi>n</mi><mo>)</mo></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msup></mfenced></mrow></semantics></math></inline-formula> for the estimation is obtained under mild conditions. As applications, the rate of uniform strong convergence and the asymptotic normality are derived.
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spelling doaj.art-c795be6d570c40df80822605f048fe232023-11-30T22:12:09ZengMDPI AGMathematics2227-73902022-07-011013232110.3390/math10132321Quantile-Wavelet Nonparametric Estimates for Time-Varying Coefficient ModelsXingcai Zhou0Guang Yang1Yu Xiang2School of Statistics and Data Science, Nanjing Audit University, Nanjing 211085, ChinaSchool of Statistics and Data Science, Nanjing Audit University, Nanjing 211085, ChinaSchool of Statistics and Data Science, Nanjing Audit University, Nanjing 211085, ChinaThe paper considers quantile-wavelet estimation for time-varying coefficients by embedding a wavelet kernel into quantile regression. Our methodology is quite general in the sense that we do not require the unknown time-varying coefficients to be smooth curves of a common degree or the errors to be independently distributed. Quantile-wavelet estimation is robust to outliers or heavy-tailed data. The model is a dynamic time-varying model of nonlinear time series. A strong Bahadur order <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>O</mi><mfenced separators="" open="{" close="}"><msup><mfenced separators="" open="(" close=")"><mfrac><msup><mn>2</mn><mi>m</mi></msup><mi>n</mi></mfrac></mfenced><mrow><mn>3</mn><mo>/</mo><mn>4</mn></mrow></msup><msup><mrow><mo>(</mo><mo form="prefix">log</mo><mi>n</mi><mo>)</mo></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msup></mfenced></mrow></semantics></math></inline-formula> for the estimation is obtained under mild conditions. As applications, the rate of uniform strong convergence and the asymptotic normality are derived.https://www.mdpi.com/2227-7390/10/13/2321quantile-waveletnonparametric estimationtime-varying coefficientBahadur representationstrong mixing
spellingShingle Xingcai Zhou
Guang Yang
Yu Xiang
Quantile-Wavelet Nonparametric Estimates for Time-Varying Coefficient Models
Mathematics
quantile-wavelet
nonparametric estimation
time-varying coefficient
Bahadur representation
strong mixing
title Quantile-Wavelet Nonparametric Estimates for Time-Varying Coefficient Models
title_full Quantile-Wavelet Nonparametric Estimates for Time-Varying Coefficient Models
title_fullStr Quantile-Wavelet Nonparametric Estimates for Time-Varying Coefficient Models
title_full_unstemmed Quantile-Wavelet Nonparametric Estimates for Time-Varying Coefficient Models
title_short Quantile-Wavelet Nonparametric Estimates for Time-Varying Coefficient Models
title_sort quantile wavelet nonparametric estimates for time varying coefficient models
topic quantile-wavelet
nonparametric estimation
time-varying coefficient
Bahadur representation
strong mixing
url https://www.mdpi.com/2227-7390/10/13/2321
work_keys_str_mv AT xingcaizhou quantilewaveletnonparametricestimatesfortimevaryingcoefficientmodels
AT guangyang quantilewaveletnonparametricestimatesfortimevaryingcoefficientmodels
AT yuxiang quantilewaveletnonparametricestimatesfortimevaryingcoefficientmodels