You alluded to it yourself. I think a lot of it is money, of course. There's no secret about that--the salary and wages you're paid. But in addition to that, I think there's a lot to be said for quality of life, and I think a lot of professionals are really valuing that now. If you're working with a skeleton crew and you're punching a lot more overtime than would be reasonable, you and your family are only going to take so much of that. I think that's where the issue of putting more resources into it and having more people share the load may help keep some people.
