I am trying to connect individuals in post-2012 IPUMS data to the county-based commuting zone in which they work using the PWPUMA variable. I poked around for a bit on the map of 2010 PWPUMA/MIGPUMAs (https://usa.ipums.org/usa/volii/10migpuma.shtml), and I could not find an instance in which a county crossed over PWPUMA boundaries. I know that PWPUMAs frequently contain several counties, but I first wanted to ask whether or not any counties cross over PWPUMA boundaries? That is, can each county be uniquely associated with a PWPUMA?
Second, while I understand that many PWPUMAs contain multiple counties and that individual level PUMS data cannot always identify a PWCOUNTY due to confidentiality, I wanted to ask if a crosswalk existed that maps counties into the PWPUMAs in which they reside. If this were the case, then it would at least be possible to map the place of work of a given individual in the ACS IPUMs samples to some set of counties. This would go a long way in identifying the commuting zone in which a person works, especially for larger commuting zones, without losing the person-level chacteristics of the PUMS data.
Thanks for all the help,