On convex least squares estimation when the truth is linear

Autor: Jon A. Wellner, Yining Chen
Rok vydání: 2016
Předmět:
Zdroj: Electron. J. Statist. 10, no. 1 (2016), 171-209
ISSN: 1935-7524
DOI: 10.1214/15-ejs1098
Popis: We prove that the convex least squares estimator (LSE) attains a $n^{-1/2}$ pointwise rate of convergence in any region where the truth is linear. In addition, the asymptotic distribution can be characterized by a modified invelope process. Analogous results hold when one uses the derivative of the convex LSE to perform derivative estimation. These asymptotic results facilitate a new consistent testing procedure on the linearity against a convex alternative. Moreover, we show that the convex LSE adapts to the optimal rate at the boundary points of the region where the truth is linear, up to a log-log factor. These conclusions are valid in the context of both density estimation and regression function estimation.
Comment: 35 pages, 5 figures
Databáze: OpenAIRE