The government definition of “unemployed” is out of work and looking for work.
This definition must stay constant for the measurement to meaningful over time.
It would be wrong to suddenly include the part-timers wanting to be full-timers, or those working below their capacity (think sociology majors working at Starbucks), or discouraged workers who are no longer looking for work.
So the government is not trying to hide anything when they quote unemployment figures. They are just being consistent, so let’s not blame them.
BTW, the broader definitions of unemployment are also made available for those who dig for it.
