2008/07/16 by Hui Zou, Runze Li · 14 citations
Computer Science · Mathematics · #Advanced Statistical Methods and Models #Machine Learning and Algorithms #Statistical Methods and Inference #math.ST #msc:62J05 #msc:62J07 #stat.TH
paper · pdf · doi:10.1214/009053607000000802
published as Annals of Statistics 2008, Vol. 36, No. 4, 1509-1533 · This paper discussed in: [arXiv:0808.1013], [arXiv:0808.1016], [arXiv:0808.1025]. Rejoinder in [arXiv:0808.1030]. Published in at http://dx.doi.org/10.1214/009053607000000802 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org)
openalex publication_date 2008/07/16 · arxiv created 2008/08/07 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
Fan & Li (2001) propose a family of variable selection methods via penalized likelihood using concave penalty functions. The nonconcave penalized likelihood estimators enjoy the oracle properties, but maximizing the penalized likelihood function is computationally challenging, because the objective function is nondifferentiable and nonconcave. In this article we propose a new unified algorithm based on the local linear approximation (LLA) for maximizing the penalized likelihood for a broad class of concave penalty functions. Convergence and other theoretical properties of the LLA algorithm are established. A distinguished feature of the LLA algorithm is that at each LLA step, the LLA estimator can naturally adopt a sparse representation. Thus we suggest using the one-step LLA estimator from the LLA algorithm as the final estimates. Statistically, we show that if the regularization parameter is appropriately chosen, the one-step LLA estimates enjoy the oracle properties with good initial estimators. Computationally, the one-step LLA estimation methods dramatically reduce the computational cost in maximizing the nonconcave penalized likelihood. We conduct some Monte Carlo simulation to assess the finite sample performance of the one-step sparse estimation methods. The results are very encouraging.