"Eventually they decided -- instead of paying people by the hour -- to just pay them per shift, and let everyone go home when they were done. Lo and behold that worked and the night teams got their packages moved around much faster and made just as much money and everyone was happy."

The problem is that such a situation is often not stable. The next boss will come in and think "these guys work only 5 hours so I either hire less people or give them more work".