For the unique household and person identifier, should we be using cpsid or hrhhid & hrhhid2?

hrhhid & hrhhid2 are in scientific notation and therfore we lose the significant digits; is there another unique household and person identifier that we should be using?

The CPSID variable is an IPUMS defined variable that uniquely identifies households across CPS samples. If you are using IPUMS CPS data, this variable (and its person-level counterpart) are best used for uniquely identifying households and persons across samples. The HRHHID and HRHHID2 variables are original CPS household identification variables provided by the US Census Bureau. When these variables are combined, they can uniquely identify households within basic monthly samples. So, I’d suggest using CPSID and CPSIDP as unique identifiers with IPUMS CPS data.