Post enumeration survey (PES) of the 15th Italian population census

The PES (Post Enumeration Survey or survey coverage) is regulated by the European Commission (Commission Regulation no. 1151/2010) that obliges Member States to provide, by March 30, 2014, estimates of the undercoverage and the overcoverage of the Population census.

This survey, globally, is carried out by many OECD countries after the end of the census operations. In recent years the techniques for carrying outpost-census surveys and statistical methodologies for estimating unknown parameters triggered a serious scientific discussion and several papers are available in the literature.

The main goal of the Italian ”PES” is to estimate the number of individuals really and usually resident at the reference time of the 15th General Census of Population and Housing (October 9th, 2011) and the coverage rate, defined as the ratio between the number of individuals found at Census (net of collective households) and the number of individuals really resident. The sampling design is a two-stage with stratification of the primary units (252 municipalities divided in self-representative and non-self-representative) and secondary units (about 2,500 enumeration areas). The survey was designed to ensure the independence of investigations (Census and PES). The households and the individuals usually resident in housing in the enumeration areas selected from the sample at the time of PES are being surveyed.

The survey took place from April to July 2012, and involved about 1,200 enumerators selected from the “best” of the Census (of course, each of them was given a different enumeration area from that processed during the Census). The PES has detected approximately 329,000 eligible individuals; an accurate phase of Record Linkage (deterministic, probabilistic and manual) between the PES and the Census and the application of a complex estimation model (Dual System model derived by ONS approach) have thus certified the high quality of the 15th General Census of population and housing.