Young Children At Very High Risk Of Being Missed In The 2020 Census Are Concentrated In A Small Number of States and ZIP Codes

Dr. Bill O'Hare

Given the changing Census outreach landscape because of the coronavirus pandemic, many organizations are altering the way they plan to reach people to promote the Census. For many Census outreach activities, ZIP Codes are a critical unit of geography. For example, for direct mail campaigns or for buying ads on Facebook, ZIP Codes are the best geographic unit to use. They are often also the best way to connect with people directly even in an epidemic, such as working with local social service agencies that are handling food distribution (grab and go style) to school children or making calls to check in with families.

Recently the Population Reference Bureau (PRB) translated the census tract database they released in February into ZIP Codes, thus allowing users to identify ZIP Codes where a large number of young children have a very high risk of being undercounted in the 2020 Census. (The census tract database is accessible here).

The PRB ZIP Code database includes the state name, the two letter state abbreviation, the state FIPS code, the five-digit ZIP Code, the number of young children (ages 0 to 4) in high risk of undercount census tracts as well as the number in very high risk of undercount Census tracts. The PRB ZIP Code database can be used to highlight areas within a state where a large number of young children are at very high risk of being undercounted in the 2020 Census. For example, one could download the portion of the ZIP Code database for California and rank the ZIP Codes by the number of young children at a very high risk of being undercounted in the 2020 Census. For Census outreach applications that rely on ZIP Code data, this provides critical data for better targeting.

The analysis here only includes ZIP Codes in the 689 large counties that were included in the PRB census tract-level database, but it should be noted these 689 counties accounted for more than 90 percent of the undercount of young children in the 2010 Census. The complete file of ZIP Code data is available here. There are more than 12,000 ZIP Codes in these counties, but only about 4,800 have census tracts where young children are at a very high risk of being undercounted in the 2020 Census. There are 34 ZIP Codes where there are more than 5,000 young children living in census tracts with a very high risk of being undercounted.

Table 1 shows the 100 ZIP Codes with the largest number of young children at very high risk of being undercounted. Each of these ZIP Codes has at least 3700 young children living in very high risk of undercount census tracts. Collectively, about 12 percent of all young children living in very high risk of undercount census tracts are in one of these 100 ZIP Codes.

In addition, these 100 ZIP Codes are clustered in relatively few states. These ZIP Codes are found in only 13 states, and eight of the states had multiple ZIP Codes. The high degree of clustering is best reflected in the fact that two-thirds of the top 100 ZIP Codes are found in just three states. The data show 27 of these 100 ZIP Codes are in New York, 20 are in Texas, and 20 are in California.

Tables 2, 3 and 4 show the ZIP Codes within these three states ranked by the number of young children in very high risk of undercount census tracts. These are places that should be given a very high priority by those trying to get a complete and accurate count of young children in the 2020 Census.

There are two ways one can find the location of a ZIP Code.

First, the location of ZIP Codes can be found at https://www.unitedstateszipcodes.org/.

Second, you can also look up ZIP Codes on the CUNY HTC Mapping system which will then give you additional information about the risk of young children being undercounted in the 2020 Census. To use the CUNY Map, go to the lower righthand corner of the home page and click on “More Map Features”, then toggle on the switches for “Undercount Risk for Young Children” and “ZIP Code” (you might have to scroll down the options to find these options). Then use the zoom feature of the map system to zoom in to the area where the ZIP Code you are interested in is located. The ZIP Code numbers and outlines will be shown on the map. Once you have located the ZIP Code, you can detect the risk of undercount for young children within the ZIP Code by looking at the color shading of the census tracts within that ZIP Code.

To get more detailed information for the census tracts within the ZIP Code you are interested in, go to the upper lefthand corner of the map home page and following “SHOW INFO FOR:” use the dropdown menu to click “tracts”. On the map, point and click on the census tract you are interested in. Click on the blue bar that says, “CENSUS DETAILS FOR TRACT_____”. Select “RISK OF UNDERCOUNTING YOUNG CHILDREN” from the dropdown menu. Scroll down the lefthand panel to see the number of children under age 5 living in that census tract and the key characteristics of that tract related to the undercount of young children.

By clicking on all the census tracts within a ZIP Code, you can identify which census tracts within the ZIP Code to give extra attention and also fine-tune your outreach strategy.

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