338 NOTE: Variance Components of Multiplicity Estimators

SUMMARY Every population survey has a rule for linking individuals to enumeration units. Conventionally, the rule uniquely links every individual to a single unit. The multiplicity estimator is based on a sample survey using a multiplicity rule that links each individual to one or more enumeration units. This estimator is particularly apropos when few individuals in the population have the attribute being measured or when the mobility or some other characteristic of individuals leads to multiple links with enumeration units. The variance of the multiplicity estimator is expressed in terms of components having interpretations that are useful in selecting multiplicity rules.