Institute of Statistical Research and Training (ISRT), University of Dhaka
Abstract
The estimation of the
slope parameter of the linear regression model with normal error
is considered in this paper when uncertain prior information on
the value of the slope is available. Several alternative
estimators are defined to incorporate both the sample as well as
the non-sample information in the estimation process. Some
important statistical properties of the restricted, preliminary
test, and shrinkage estimators are investigated. The performances
of the estimators are compared based on the criteria of
unbiasedness and mean square error. Both analytical and graphical
methods are explored. None of the estimators is found to be
uniformly superior over the others. However, if the non-sample
information regarding the value of the slope is close to its true
value, the shrinkage estimator over performs the rest of the
estimators