The Reliability of Repeated Measures of Retrospective Parity and Birth Dates in U.S. Survey Data: A Research Note.

In a longitudinal survey, most people consistently report parity and birth date information. One in 10 respondents, and one in five parents, report parity inconsistently across waves. Among those who reported children at an earlier wave, 11% report different dates of first birth. Inconsistency in parity and first birth dates was higher among males and less advantaged people.