After @Sophia_Autor 's last message, we asked that the IPUMS USA team take a closer look at all of the component pieces of the POVERTY variable. It seems that there is a double-inflation issue as @scogginj suggested. I hope to provide a more detailed update about the source of the error (as well as an offer of an IPUMS mug to those who helped us flag the error) in the next few days. Thanks for your ongoing patience.