This paper is the first to investigate how the coverage of young Hispanic children in the 2020 Census varied by county, and it contributes to the literature on the count of Hispanics in the U.S. Census.
The study found that there was considerable variation in the coverage rates for young Hispanic children across counties. However, most of the counties (63 percent) had a net undercount of young Hispanic children, and the vast majority (86 percent) of young Hispanic children resided in a county with a net undercount of young Hispanic children.
Net undercounts are widespread, with 41 of the 51 states (and DC) having a net undercount of young Hispanic children. This contrasts slightly with the net coverage of all young children in the 2020 Census, in which every state had a net undercount (U.S. Census Bureau 2024c).
With a slight overcount, the Midwest region was an outlier regarding census coverage of young Hispanic children with a light overcount. This raises questions about why the results are so different from the rest of the country.
The net undercount of young Hispanic children is concentrated in a relatively small number of states and counties. The study found that just six states account for 76 percent of the net undercount of young Hispanic children, and the 50 counties with the highest net young Hispanic child undercount numbers account for 72 percent.
There are high net undercount rates in counties of a million or more people for both young Hispanic children (10 percent) and all young children (9 percent). However, for small counties (those under 20,000 total population size), young Hispanic children have much higher net undercount rates compared to all children in smaller counties.
It is not clear why young Hispanic children have such a high net undercount, but some evidence on this question has emerged.
Census data collected through self-response is generally more accurate than data gathered during the Nonresponse Follow-up (NRFU) phase. (Brown et al., 2019). A recent Census Bureau publication (2024e) found that the 2020 Census return rates for households headed by a Hispanic (58.6 percent) were substantially lower than the return rate for households headed by a non-Hispanic person (81.8 percent).
Research by Quiros and O’Hare (2024) identified several variables that are highly correlated with variation in state-level coverage rates for young Hispanic children, including the state’s racial/ethnic composition, some housing measures, variations in family structure and living arrangements, and socioeconomic status. Sorting out the independent effects of all these factors will be difficult.
The data from the Census Bureau used for this analysis does not distinguish among Hispanic subgroups such as Mexicans, Puerto Ricans, and Cubans. If we could disaggregate coverage of the Hispanic population, differences may help us understand why some Hispanics are missed at a high rate in the Census.
The data shown here raises issues of data equity by focusing on subnational accuracy measures. Some parts of the country have much more accurate data on young Hispanic children than other places in the country. The fact that these figures are tied to trillions of dollars in federal government aid elevates the importance of this variation in quality.
A better understanding of the geographic distribution of the undercount rates for young Hispanic children and factors associated with the undercount of young Hispanic children may help us pinpoint why young children have such a high net undercount rate, determine which young children are most vulnerable to being undercounted, and will better prepare us to reduce this problem in the 2030 Census by focusing outreach efforts more effectively.
Previous U.S. Censuses (1990, 2000, 2010, and 2020) have consistently undercounted Black and Hispanic populations (all ages) (Stempowski, 2023), so the high net undercount of young Hispanic children shown in this paper is consistent with broad research on Census coverage. This is not a new issue. Much work is needed to get an accurate count of young Hispanic children in the 2030 Census. This study will help stakeholders and the Census Bureau focus outreach and targeting in the 2030 Census to help reduce the high net undercount of young Hispanic children.
