I am examining labor force participation in 25-34 year olds using CPS ASEC samples from 1962-2016. In all years, several hundred of these respondents have a value of 0 (NIU) for LABFORCE.
But according to the documentation, the universe of this variable is either persons 14+ or persons 15+, depending on the year. Is that in fact not the correct universe?
Besides age restrictions, which don’t apply to your sample of 25-34 year olds, the LABFORCE variable is restricted to only those who make up the civilian labor force. Thus all those who are employed by the armed forces, identified as “Armed Forces” in EMPSTAT, are NIU in LABFORCE. In fact, in your restricted sample, all of the NIUs in LABFORCE are identified as being employed by the Armed Forces.