The PES results released today also provide coverage errors by race and ethnicity.

These results showed statistically significant undercounts for the following populations: Black or African American alone or in combination, American Indian or Alaska Native alone or in combination, the Some Other Race alone or in combination, and Hispanic or Latino.

The PES found statistically significant overcounts for the White alone or in combination, Non-Hispanic White alone, and Asian alone or in combination populations. We did not find a statistically significant overcount or undercount for the Native Hawaiian or Other Pacific Islander population.

Although people may want to know whether there was an undercount specifically for their city or neighborhood, it’s important to note that the coverage measurement programs are not that geographically precise: both the PES and DA are currently only available at the national level.  

However, additional PES results for the total population for states will be available this summer. The PES will not release metrics below the state level. Experimental estimates for DA at the state and county level for the population ages 0 to 4 will also be released at a later date.  

Depending on the series, the DA results show both an undercount and overcount nationally. 

• The DA net coverage error estimate was 0.22% (a slight overcount) for the Low Series, which includes less international migration, less population in the oldest ages, and fewer historical births than the other series. 
• The net coverage error estimate for the Middle Series is -0.35% (a slight undercount).
• The High Series, which has higher international migration, more population in the oldest ages, and more historical births, shows a net coverage error of -1.21%.   

As seen in Table 1, the results for the national population in the 2020 Census were similar to the 2010 Census where we did not see a statistically significant overcount or undercount in the PES results and the DA range included both undercounts and overcounts.  

However, more variation in the coverage patterns for the 2020 Census becomes evident when we look at the results by demographic characteristics, housing tenure and components of coverage.  

There is a lot of variation across the DA series for the oldest ages where the net coverage error estimates show large overcounts in the Low and Middle series and undercounts in the High Series.  

The estimates for the age 75-and-older group are unique because we use Medicare enrollment records and not birth records to produce the population estimates (see the DA methodology statement for details on why this is).

The range for these older age groups was produced by making adjustments to the Medicare records to account for under-enrollment.  

We see large overcounts for certain ages and large undercounts for the surrounding ages. This pattern is caused by “age heaping” in the 2020 Census results.  

Age heaping refers to distortions in the age distribution of a population where the number of ages reported that end in 0 and 5 (e.g., 20, 25, 30, 35…) is higher than would be expected.  

Age heaping often happens when people are reporting for someone else — either another member of their household, or a neighbor giving a proxy response.  

Think about it this way: If you don’t know exactly how old someone is, you are more likely to guess rounded numbers like 45 or 50 than 46 or 49.  

A major contrast that we see between PES and DA results is for males and females ages 18-29. In both categories, the PES shows a statistically significant undercount while the DA estimates show an overcount for these populations, except for the High series for males. For these ages, the difference is that the High series assumes more international migration than the other series.     

When we break down the DA net coverage error estimates for these males and females even further, we see that there were large overcounts for the 18-24 age group, but undercounts for the 25-29 age group. The PES estimates for these smaller age groups are not available.  

The DA estimates are produced for the total population living in the United States on April 1, 2020, while the PES estimates are produced for the household population living in the United States excluding Remote Alaska areas.

A lot of people in the 18-24 age group live in college dorms, which are not part of the PES sample. Research is underway to explore the differences between the DA and PES results for these ages.

The PES and DA estimates of net coverage error for adults ages 30-49 show similar patterns. Males in this age range showed an undercount in DA and a statistically significant undercount in PES.  

PES found a statistically significant overcount for both males and females 50 years and older but the net coverage error estimate for females was larger than for males.

We see similar results for DA where, except for the High series for males, the net coverage error estimates show an overcount.