Improvement estimation on two successive occasions in cluster sampling

In this paper we attempt the problem of estimation of the sum of mean and the change of mean in mail surveys. This problem is conducted for current occasion in the context of cluster sampling over sampling on two successive occasions. The sampling units are clusters and the observations on the first occasion are regarded as ancillary information for the observations on the second or current occasion. The results obtained are demonstrated with the help of an empirical study, which reveals that under certain condition, the cluster sampling on two occasions is more efficient than the simple random sampling on two occasions.