Thanks so much for the helpful information and links! The final PUMA criteria document was something for which I had been looking.
I do have a followup on the second point, though. As you suggest, for those PUMAs which relate to the subset of identifiable categories, it seems straightforward enough to connect a PWPUMA to a county. This is helpful, but not exactly what I want to do. Rather, I want to connect each PWPUMA with the set of counties it is composed of. That is, I want to use the PWPUMA variable to connect an individual with the set of counties in which they could possibly be working. I know that I cannot associate each individual with a unique county of work, but since PWPUMA boundaries are tied to county boundaries, it seems possible to at least connect each individual with the larger(contiguous) set of counties in which the work, as defined by PWPUMA.
Is this the case? If so, how might I go about finding which counties compose with PWPUMAs?
Thanks again