I am trying to get county-level data on California householder's racial composition. My variable of interest is HHLDRRAC1P. However, I can only select
STATE
or PUMA
data.census.gov/.../
How can I select county, or aggregate to get county-level estimates that are appropriately weighted?
As a general matter you can't get county level estimates from PUMS data. The only geography for PUMS data is the PUMA. In the case where a county is a "Union" of several PUMAs you can "stack" PUMS data for the corresponding PUMAs. If the PUMAs cross county lines you are stuck.
Where can I get county-level?
Try
The unit of analysis is the household not the person. For example if you want to know the population in households where the householder is African American you can't get it from this table.
I think that you have to use pums data where this a linkage between the householder and the members in the householder using PUMS variables SERIALNO and SPORDER
Dave