Should I give up a supplemental income I was promised (in writing) to help restore my supervisor's budget?

Alan, I suppose your intent is quite noble, but I would disagree with the solution of relinquishing your supplement. What you propose is pretty much Karl Marx and we all know how well that works. The proper action is to address the issue of who didn't "well manage" or develop the budget. IMO, insist upon them keeping their agreement. RJ