Two young kids and their parents walking out in nature

Reducing the Undercount of Young Children in Census 2020

At least 4 million U.S. children under age 5 live in neighborhoods with a very high risk of undercounting young children in the 2020 Census.

WASHINGTON, D.C. – At least 4 million U.S. children under age 5 live in neighborhoods with a very high risk of undercounting young children in the 2020 Census, according to a new analysis by Population Reference Bureau (PRB). The estimate is based on a new PRB study to help improve targeting of communities with the highest risk of undercounting young children. In the study, PRB identifies factors that predict where children under age 5 are more likely to be missed and develops a new undercount risk measure for young children. A database and interactive map show the risk of undercounting young children across census tracts in 689 large counties.

Note to Editors: Maps showing the risk of child undercount in 12 large counties and cities including New York, Washington, D.C., Houston and Las Vegas are available.

PRB results suggest that two measures currently being used to identify areas where young children are more likely to be missed—the 2010 Census mail return rate and the Low Response Score (also based on mail return rates)—are not very good predictors of net undercount rates for young children in large counties. Using updated census data for the 689 counties, the new study points to data on family structure and living arrangements, recent immigration and socioeconomic status as better predictors of the risk for child undercount.

“Developing this new risk measure for the undercount of young children in local communities is a big step forward,” said Linda Jacobsen, co-author of the study and PRB’s vice president for U.S. Programs. “It provides advocates and others with a new tool to better pinpoint neighborhoods that need special attention.”

While the net undercount rate for adults has fallen significantly over the last four decades, the rate among young children under age 5 has increased and remains stubbornly high. The 2010 Census saw a net undercount of almost 1 million young children, and their undercount rate of 4.6% was more than twice the rate of other age groups.

“It’s a critical issue,” said William P. O’Hare, co-author of the study. “When young children are missed in the census, communities do not get their fair share of resources for things like schools, healthcare and childcare facilities. Unfortunately, children most in need of this kind of support are often living in the places that are underfunded because of census undercounts.”

“The net undercount of children in Washington, D.C. was 16% in the 2010 Census,” said Dr. Kimberly Crews, assistant professor at the University of the District of Columbia and a member of the city’s Complete Count Committee. “This database and interactive map will help frontline organizations target day care centers, Head Start programs and families in neighborhoods with the greatest need for equitable resources.”

Collectively, the 689 counties included in the study account for about 93% of the national net undercount of young children in the 2010 Census. After identifying factors associated with the undercount of young children at the county level, PRB applied model coefficients to more recent population data at the census-tract level to identify neighborhoods at varying levels of risk for child undercount.

Young children are more likely to be missed in neighborhoods with high shares of:

  • Children living in poverty.
  • Adults ages 18 to 34 without a high school diploma or GED.
  • Children living in female-headed households with no spouse present.
  • Young children living with grandparent householders.
  • Households that are limited English speaking.
  • Children living in immigrant families.
  • People living in renter-occupied housing units.


Data for this study are based on PRB’s analysis of the Census Bureau’s Revised 2018 Experimental Demographic Analysis Estimates and five-year estimates from the American Community Survey. The technical paper with full methodology and the database are available.




About Population Reference Bureau (PRB)
Contact: Liselle Yorke, 202-939-5463
PRB informs people around the world about population, health, and the environment, and empowers them to use that information to advance the well-being of current and future generations. Find out more at Follow us on Twitter @PRBdata.