The Forever War

None. Relativistic time dilation does the work automation usually does.

Mandella returns from combat to an Earth of mass unemployment and state rations, where the economy has restructured around having no use for him. He re-enlists, because the army is the only institution that still has a slot with his name on it.

Obsolescence — The work goes, and standing goes with it.

The displacement here is caused by decades passing, not by machines — but the returning soldier's problem is exactly the redundant worker's problem, and Haldeman writes it better than most.