Young children are undercounted in the census at a higher rate than any other age group

Young children – defined as children under age five – have been undercounted for decades, disadvantaging their families, communities, and neighborhoods. In the 2010 Census, the net undercount rate for young children was 4.6 percent, and more than 2.2 million in this age group were not included in the census results. This is a higher net undercount rate than for any other age group. Even among other children, those under five years old are more likely to be missing from census data.

Some young children are especially at risk of being missed

Some groups of young children, depending on their race, ethnicity, or even where they live, have higher-than-average undercounts. Young Black and Hispanic children have the highest net undercounts. Experts estimate that approximately 6.5 percent of young Black and Hispanic children were overlooked by the 2010 Census, roughly twice the rate for young non-Hispanic White children.

Young children living in certain geographic areas are at particular risk of being undercounted. For instance, the 2010 Census undercounted children under age five in Arizona by 10 percent, but overcounted them in North Dakota by 2.1 percent. Therefore, a young child in Arizona may not be afforded the same resources as a similar child in North Dakota when census data are used to distribute federal funds. One study found that in the nation’s largest counties (those of a half million people or more), the net undercount for young children was nearly 8 percent—almost twice the national rate.