Trouble Reproducing B19126

Hi IPUMS,
I successfully recreated ACS Table B19126 using 2019 - 2023 5-year PUMS with weighted interpolation and the Census methodology, it falls within the MOEs.

But when I apply the same method to 2014 - 2018 or 2009- 2013, the values for subgroups like married-couple families with own children don’t fall within the published MOEs.

I’ve used HHT, NOC, and adjusted FINCP correctly (I believe), but something’s still off. Has anyone here recreated B19126 for earlier 5-year files? Would love to know if there’s something I’m missing – maybe changes in variable definitions or universe?

Thanks in advance!

It’s common for ACS summary table estimates and those derived from the public use microdata to slightly differ. Several factors contribute to this, including the fact that the public-use file is a subset (about 2/3) of the full restricted use dataset. In the case of income variables, differences can be more pronounced due to topcoding in the public data. This is especially relevant for aggregate income measures like FINCP, which is calculated by summing the income components of each family member (each of which is individually topcoded). As a result, income estimates in the PUMS can diverge from those in the published tables, sometimes even falling outside the reported margin of error.

Regarding the effect of changes to family definitions, one possibility might be that this is caused by changes in the relationship to householder variables over time. In 2019, the Census Bureau added some more clarity to the spouse/partner response categories that may have resulted in less data editing and fewer reporting errors (see this PRB overview). Additionally, the 2009-2013 data may be impacted by the inclusion of same-sex married couples (in the 2013 data only). I am unsure how the multi-year summary files handle these changes; it may be that the tables implement the change for all years while in the PUMS the change is only applied to the years after it is implemented.

It would be helpful to know your specific estimates for the 2013 and/or 2018 files to better understand the extent of the discrepancy. You might also consider calculating confidence intervals for your PUMS-based estimates using replicate weights (see REPWT). Even if your point estimates fall outside the published MOEs, there may still be overlap between the confidence intervals derived from the microdata and those in the published tables when using replicate weights.