[ghaff]

Well, it's not 80% pay given benefits and overhead costs associated with having an employee. Probably more like a 30%+ cut.

ADDED: Assuming it really is a 20% cut in productivity which, for office workers, probably isn't the case but would be for many others including white collar jobs like lawyers, doctors, consultants, etc.

[IshKebab]

Yeah mean a 15% cut right, because the fixed overheads stay the same? Yeah that's probably why most employers aren't keen on it.