Abstract
A number of applications, including claims made under Federal social welfare programs, require retrospective sampling over multiple time periods. A common characteristic of such samples is that population members could appear in multiple time periods. When this occurs, and when the marginal cost of obtaining multiperiod information is minimum for a member appearing in the sample of the period being actively sampled, then a method which is herein called progressive random sampling (PRS) may be applied. The proposed method serves to either improve sampling estimates or reduce sample sizes, as demonstrated by two example applications.
