The Pervasive Nature of Under-Reporting Young Children in Official Data

As we start to prepare for the dissemination of the 2020 Census data, it is a good time to remind ourselves of the extent to which young children are missed or overlooked in many official data collection activities.   In the 2010 Census, young children (ages 0 to 4) had a higher net undercount (4.6 percent) than any other age group.  But in some ways that is just the tip of the iceberg.

Not only are young children undercounted in the U.S. Census at a higher rate than any other age group, but they are also under-reported in U.S. Census Bureau surveys (such as the American Community Survey, Current Population Survey of Income and Program Participation) at a higher rate than other age groups.  In addition, the most recent data available indicate young children are under-represented at a higher rate than other age groups in the administrative records used by the Census Bureau.  Finally, the under-reporting of young children is not just a problem in the U.S. Census. The undercount of young children in Censuses is seen in many different countries.

This short paper provides evidence for the points made above and provides citations for more detailed data on each point.