Abstract
The consistency of classical local linear kernel estimators in nonparametric regression is proved under constraints on design elements (regressors) weaker than those known earlier. The obtained conditions are universal with respect to the stochastic nature of design, which may be both fixed regular and random and is not required to consist of independent or weakly dependent random variables. Sufficient conditions for pointwise and uniform consistency of classical local linear estimators are stated in terms of the asymptotic behavior of the number of design elements in certain neighborhoods of points in the domain of the regression function.
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Notes
In the Russian-language literature, the term “deterministic design” is often used.
This means that, with probability \(1\), \(c_1h\leq \lim\sup_{ t\in[0,1]}\#(N_{n,h}(t))/n\leq c_2h\), where the constants \(c_1\) and \(c_2\) do not depend on \(t\) and \(h\).
This means that \({\mathbb P}\bigl(\#(N_{n,h}(t))/(nh)\in [c_1,c_2]\bigr)\to 1\), where \(c_1>0\) and \(c_2>0\).
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Acknowledgments
The author thanks the referee for the careful reading of the manuscript as well as for comments and remarks.
Funding
This work was supported by the Program of fundamental scientific studies of the Siberian Branch of the Russian Academy of Sciences (grant no. FWNF-2022-0015).
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Translated from Matematicheskie Zametki, 2023, Vol. 114, pp. 353–369 https://doi.org/10.4213/mzm13906.
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Linke, Y.Y. On Sufficient Conditions for the Consistency of Local Linear Kernel Estimators. Math Notes 114, 308–321 (2023). https://doi.org/10.1134/S0001434623090043
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DOI: https://doi.org/10.1134/S0001434623090043