Ridge Estimation in Linear Regression.
Abstract
Consider the linear regression model Y = X Theta + epsilon. Recently, a class of estimators, variously known as ridge estimators, has been proposed as an alternative to the least squares estimators in the case of collinearity, that is, when the design matrix X'X is nearly singular. The ridge estimator is given by Theta-cap = (1/(X'X + KI)) X'Y, where K is a constant to be determined. An optimal choice of the value of K is not known. This paper examines the risk (mean squared error) of the ridge estimator under the constraint Theta'Theta < r or = c and determines optimal values of K for which the risk is smaller than the risk of the least squares estimators where c is a constant. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1976
- Accession Number
- ADA083521
Entities
People
- James S. Hawkes
Organizations
- Clemson University