If you are examining individual level data, can you use the state FIPS codes? is it preferrable to use the PW Metro codes instead?
It is completely acceptable to use the Household-level variable STATEFIP for a person-level analysis. This information is automatically placed on the person record of everyone in the household so it is not necessary to perform any transformation either. PWMETRO is a person-level variable because different people within a single household can work in different metropolitan areas.
I hope this helps.