All prison inmates are basically unemployed.
LOL, I don’t think they count.
Quick story: Your sector dries up and you’re let go from your job. You are unemployed. You can get unemployment checks for 26 weeks. (varies by state?) You still haven’t found a job in your sector after the 26 weeks. You are now not unemployed, you’re no longer in the labor force. Unemployment and labor force participation rates go down.