Having started on the night shift in the position I was hiring for, I felt it was good. Emphasis on the “keeping people” part of it. Hardly anyone (except this one guy) wants to stay on the night shift forever, and eventually no amount of shift differential will make up for it. Personally, I would much rather hire people from around the world since the work could be done remotely, so that no one has to work in the middle of the night.

Pretty easy to be flippant with “just pay more” without considering the realities of people’s preferences, how much I was able to offer before I was told no more, the quality of the people applying, the skills required, etc.