Some Improved Estimators of Population Mean using Two-Phase Sampling Scheme in the Presence of Non-Response.

In the present paper, we have proposed some improved estimators of the population mean utilizing the information on two auxiliary variables with the use of two-phase sampling scheme under non-response. We have discussed the situation in which study and first auxiliary variables suffer from the non-response while the second auxiliary variable is free from the non-response. The expressions for the bias and mean square error of the proposed estimators have been derived up to the first order of approximation. We have compared the efficiency of the proposed estimators with that of the usual mean estimator and some well known existing estimators of the population mean. The theoretical results have also been illustrated through some empirical data. [ABSTRACT FROM AUTHOR]