Ratio and regression estimation use additional information that is known about the population to improve the accuracy of estimators. This chapter shows, with code and output for the examples from Chapter 4 of Sampling: Design and Analysis, Third Edition, how to use the RATIO statement in the SURVEYMEANS procedure of SAS® software to calculate ratios and ratio estimates of the population mean and total. The SURVEYREG procedure is introduced for computing regression estimates of population means and totals.

Statistics about subpopulations (domains), such as the percentages of persons in each age group having a specified characteristic, are special cases of estimating ratios because the denominator giving the subpopulation size varies from sample to sample. Examples are given for using the DOMAIN and POSTSTRATIFY statements to calculate domain statistics and to calculate poststratified estimates.