Research Note: Babies Born After Census Day: How the Census Bureau Addressed Dates of Birth After Census Day in the 2010 Census.

The fundamental purpose of the decennial Census is an enumeration of the U.S. population at a particular 'Census moment' for the purpose of apportionment. The 'Census moment' for the 2010 Census occurred at 11:59 p.m. on April 1, 2010. This means that, ideally, all persons alive and living in the United States at that moment are included in the Census count, while any person not alive at that moment is excluded. In reality, this goal is challenging to achieve. Since the actual date of data collection often varies widely, it is possible that individuals are included, or excluded, in the count due to this discrepancy between the Census Day and the date of data collection. In this paper, I explore how the Census Bureau addresses this issue specifically when dates of birth after Census Day are encountered. First, I describe the three methods of data collection (Self-administered questionnaires, enumerator-administered questionnaires, and Telephone Questionnaire Assistance/Coverage Follow-Up operator-administered questionnaires), and how dates of birth after Census Day are addressed in each of these methods. Next, I explore related findings from the 2010 Census, including how many dates of birth after Census Day were found in the 2010 Census data, how they were processed according to data collection method, and how this impacted the final Census count. Finally, I discuss the performance of the new procedures related to dates of birth after Census Day that were implemented in the 2010 Census, along with implications for moving forward into future Censuses. [ABSTRACT FROM AUTHOR]