Incorporating the auxiliary information available in variance estimation

A difference estimator using an auxiliary variable x is defined to estimate the finite population variance Sy2 of the study character y. Classical difference type estimators use auxiliary information based on a single auxiliary parameter, specifically the parameter of interest, associated with the auxiliary variable. In practice, however, several parameters for auxiliary variables are available. This paper discusses how such estimators can be modified to improve the usual methods if information related to other parameters associated with an auxiliary variable is known. A simulation study is carried out to demonstrate the superiority of the suggested estimator over the others.