Economics Homework Help

I’m working on a economics question and need an explanation and answer to help me learn.

Assume your neighbor is a doctor. He complains bitterly about the overtime that he is putting in at the hospital each weekend. While the overtime is not required, he argues that by not taking it he would be sacrificing $1,000 each weekend. If he were to ask for your opinion about what to do, what would you advise him?