cps occupation missing codes

#1

we are looking at the ipums 1990 data. we see that occupational code is not missing for any observations, and there seems to be no code for missing. yet, it is hard to believe that all respondents with a job chose to answer this question. please help interpret.

#2

While there is no code for “missing”, there are codes for “No occupation”==000 and “Unemployed or armed forces”===905. For occupation data, the CPS interviewer collects information by asking what kind of work the person was doing, and Census Bureau staff codes the responses into the occupation coding classification scheme. This may help explain the lack of missing observations.