I’m finding the variable on the micro-data level to analyze the wireless-only (cell-phone-only) household as the NHIS early release reports depicted about “wireless substitution”(https://www.cdc.gov/nchs/data/nhis/earlyrelease/wireless201812.pdf). NHIS is providing this report starting from 2003.
In NHIS documentation, the variable CURWRKN from 2006 to 2018 provides this information by gathering responses to the question “Is there at least one telephone INSIDE your home that is currently working and is not a cell phone?” and variable CURWRK from 2003 to 2006 provides this information by gathering responses to the almost the same question.
In IPUMS NHIS dataset, I find the harmonized variable TELNONCEL is provided combining CURWRK (2003-2006) and CURWRKN (2007-2010), which provide a easier way to study “wireless-only household” across years. However, this variable is not available for data after 2010.
Additionally, I find the variable CURWRKN with data available after 2010 (2007-2018) is actually combined with INSIDE (before 2007) together as TELEPHONE variable. Apart from not including “is not a cell phone”, the INSIDE question in NHIS questionnaire asks the similar question about telephone inside home.
I find the fact that the variable TELNONCEL is not available after 2010 is quite confusing. At the beginning, I thought it was NHIS that stopped to ask this questions after 2010. It took me quite a while to find that information about this question is still available after 2010 but in another variable called TELEPHONE. I think a few sentences explaining this situation added in the variable description page, if it would not cause too much trouble to IPUMS team, will make it more convenient for other users.
What’s more, the description for the variable TELEPHONE is “Household has telephone”, which is not accurate. After 2006, TELEPHONE is using CURWRKN and I think that survey question is asking about the family characteristics instead of household characteristics. I also find out from the data downloaded from IPUMS NHIS that people in the same household (cases same NHISHID) but from different family (different FMX) can have different value for TELEPHONE.
Hope it makes sense. Thanks!