Postenumeration

Postenumeration, or post-enumeration, refers to the set of activities conducted after a population census or large-scale enumeration to assess the accuracy of the counts and to estimate any coverage errors. The central component is the post-enumeration survey (PES), a separate sampling interview designed to measure undercount and overcount and to provide a basis for evaluating data quality. This approach is used to produce an independent check on census results and to inform improvements in methodology for future censuses.

A PES typically selects a probability sample of housing units or individuals and re-contacts them after the main census operation. Respondents are asked about people who were counted in the census and about people who were not; the findings are linked with the census records to estimate net coverage error, misclassification, and duplication. The analysis often involves statistical matching and weighting to produce estimates of census completeness and of demographic indicators adjusted for known errors.

The results may be used in different ways depending on the country. Some statistical agencies use PES results to adjust official population totals or to calibrate weighting schemes in demographic estimates. In others, the PES serves as a quality audit without altering the published census counts. Regardless of use, PES helps quantify uncertainty, guide methodological improvements, and inform public discussions of census reliability.

Limitations include the cost of conducting a separate survey, potential sampling and matching errors, and the possibility that PES cannot capture all sources of inaccuracy, such as misreporting within households or errors in the original enumeration frame. Despite these limits, postenumeration remains a standard tool in census methodology for evaluating and improving population data quality.