Absenteeism is visible and measured; presenteeism is invisible and, by cost estimates, larger. One appears in a spreadsheet; the other appears as work that quietly takes longer and needs redoing.
Side by side
Aspect
Presenteeism
Absenteeism
Visible
No
Yes
Measured
Rarely
Routinely
Estimated cost
Larger
Smaller
Punished
No
Often
What each one means
Presenteeism
Being at work while too unwell to work properly, and getting less done than the hours suggest. An older sense, still in dictionaries, is simply staying at work beyond the hours the job needs. The productivity loss nobody logs.