DOI link for Stratified Sampling
Stratified Sampling book
The survey sampler may know additional information about the population before sampling, such as the gender and major of every student at a university, the percentage of persons in each county who are age 65 or older, or the dollar amount of every loan made by a bank. Stratified sampling uses this additional information about the population to improve the efficiency of the survey design. This chapter provides example code for using the SURVEYSELECT procedure in SAS® software to allocate and draw stratified samples from a population with proportional, Neyman, optimal, or custom allocation. Statistics from stratified random samples are calculated with the SURVEYMEANS and SURVEYREG procedures; code and output are given for examples from Chapter 3 of Sampling: Design and Analysis, Third Edition.