The effect of using household as a sampling unit

The effect of sampling people through households is considered. Results on design effects for two stage surveys are reviewed and applied to give design effects of household sample. The main factors that determine the design effect are identified for the designs in which one person, or all people, are selected from each selected household. Within household correlation is one factor. We show that the relationships between household size and the mean and variance within households are also important factors. Census and survey data are used to empirically compare the design effects for a range of estimators, variables and designs.