Both HHTENURE and OWNERSHP are available in ASEC CPS and both are household-level variables reflecting housing tenure, but their case counts are different. What is the difference between these two variables?
HHTENURE and OWNERSHP both use data from the same original CPS variable, h_tenure. HHTENURE harmonizes this variable so that codes are consistent over time; OWNERSHP additionally imposes an interview requirement that recodes non-interviewed units to NIU (OWNERSHP = 0) regardless of whether the household tenure category had been determined.
The frequencies displayed on the variables pages for these reflect household-level counts; you can view the universe tab to see which types of households are included in the universe. Note that the IPUMS CPS extract system will default to delivering a person-level extract with household-level measures appended to the person record. Accordingly, frequencies tabulated from an extract will not match the website both because they reflect person-counts and because the default format relies on a person residing in the household and will omit vacant households. To match the frequencies displayed on the website or track vacant units you will need to change the data structure for your extract to “Hierarchical” instead of “Rectangular” (on the person-level).