Owen Robinson deals with the issue of a mandatory "prevailing wage" at length. No, really. At length.
Just remember, “prevailing wage” laws are not about making sure people are paid fairly. It’s about making sure that non-union labor - including volunteers - doesn’t have a competitive advantage through lower prices. In the end, it just means more money out of the pockets of taxpayers transfered into the pockets of the unions. And because of the higher cost of labor, fewer projects will be completed.