Guidance on using CBPOVERTY to replicate published Census ACS poverty tables

Hello forum,

I am calculating the official poverty rate using the ACS data and I found a discrepancy between the calculated estimates and the published Census ACS table when using CBPOVERTY in a particular way.

According to the guidance given on the IPUMS variable page, CBPOVERTY == 0 should be excluded from the analysis as those observations are documented as missing, however if you restrict a sample under this methodology (CBPOVERTY > 0) the estimated poverty rate is too low. After some digging through the IPUMS forum I found a post from 2025 outlining the appropriate restrictions for using the CBPOVERTY variable to match published data, specifically to include GQ == 5. When I changed the restrictions from CBPOVERTY > 0 to GQ == c(0:2, 5) I was able to get the data to converge to published estimates, including (and in particular interest to me) by state. Here are my national results below:

Year Published poverty rate Estimated poverty rate: CBPOVERTY > 0 Estimated poverty rate: !GQ %in% c(3, 4)
2024 12.1% 10.3% 12.1%
2023 12.5% 10.6% 12.5%

Note that throughout my analysis I am using an indicator variable for “poverty_1x” which is defined as 1 if CBPOVERTY < 100 and 0 otherwise to produced “Estimated poverty rate.”

I am concerned that the data that does converge to published data (right-most column) still includes households (but not group quarters) with CBPOVERTY == 0 due to how poverty_1x is defined, which diverges from the guidance in the IPUMS forum post linked above. To be clear, if I edit poverty_1x to be defined as 1 if 0 < CBPOVERTY & CBPOVERTY < 100 per the forum guidance the estimates follow the same trend as the middle column (CBPOVERTY > 0).

I’m wondering if anyone at IPUMS has any insight into how this variable is constructed and if these restrictions and approach/methodology seem appropriate.

Thank you for bringing this to our attention. After reviewing the data, it appears that values of zero for CBPOVERTY are currently grouping two types of respondents: (a) those who are outside of the poverty universe and (b) those who are in the poverty universe and have family incomes of $0. I have shared this finding with my colleagues who will work on revising our processing of CBPOVERTY so that these two groups are separately identified. This affects the 2023 and 2024 ACS samples, but does not appear to be an issue in previous years.

It is possible to separately identify the 0 and not-in-universe groups using the source variable for CBPOVERTY, POVPIP. Source variables provided the original unharmonized variables that are the inputs for IPUMS harmonzied variables. Since source variables are specific to each sample, you will want to add the source variable that corresponds to your sample of interest (i.e., US2024A_POVPIP for 2024 and US2023A_POVPIP for 2023) to your data cart. Observations that are not in the poverty universe will have POVPIP = “BBB” while those in the universe with $0 income with have POVPIP = 0.

It is also possible to separately identify these two groups using the variables that describe the poverty universe. After restricting to CBPOVERTY = 0, there are three sub-groups that comprise individuals who are not in the poverty universe:

1. Persons with GQ = 3 (those in institutional group quarters).

2. Persons with GQ = 4 who are currently enrolled in school (SCHOOL = 2); these are students residing in campus dorms. Note that this means that remaining group quarters persons are included in the poverty universe.

3. Persons in households (GQ = 1, 2, or 5) who are not related to the householder (RELATE = 11-13) and are under the age of 15 (AGE 0-14).