Electronic Journal of Statistics
- Electron. J. Statist.
- Volume 5 (2011), 127-145.
PAC-Bayesian bounds for sparse regression estimation with exponential weights
Pierre Alquier and Karim Lounici
Abstract
We consider the sparse regression model where the number of parameters p is larger than the sample size n. The difficulty when considering high-dimensional problems is to propose estimators achieving a good compromise between statistical and computational performances. The Lasso is solution of a convex minimization problem, hence computable for large value of p. However stringent conditions on the design are required to establish fast rates of convergence for this estimator. Dalalyan and Tsybakov [17–19] proposed an exponential weights procedure achieving a good compromise between the statistical and computational aspects. This estimator can be computed for reasonably large p and satisfies a sparsity oracle inequality in expectation for the empirical excess risk only under mild assumptions on the design. In this paper, we propose an exponential weights estimator similar to that of [17] but with improved statistical performances. Our main result is a sparsity oracle inequality in probability for the true excess risk.
Article information
Source
Electron. J. Statist. Volume 5 (2011), 127-145.
Dates
First available in Project Euclid: 14 March 2011
Permanent link to this document
http://projecteuclid.org/euclid.ejs/1300108317
Digital Object Identifier
doi:10.1214/11-EJS601
Mathematical Reviews number (MathSciNet)
MR2786484
Zentralblatt MATH identifier
1274.62463
Subjects
Primary: 62J07: Ridge regression; shrinkage estimators
Secondary: 62J05: Linear regression 62G08: Nonparametric regression 62F15: Bayesian inference 62B10: Information-theoretic topics [See also 94A17] 68T05: Learning and adaptive systems [See also 68Q32, 91E40]
Keywords
Sparsity oracle inequality high-dimensional regression exponential weights PAC-Bayesian inequalities
Citation
Alquier, Pierre; Lounici, Karim. PAC-Bayesian bounds for sparse regression estimation with exponential weights. Electron. J. Statist. 5 (2011), 127--145. doi:10.1214/11-EJS601. http://projecteuclid.org/euclid.ejs/1300108317.

